Cerebrospinal Fluid (CSF) Biomarkers Overview

Introduction

This biomarker category is relevant to:

• Alzheimer’s Disease — Aβ42, total tau, p-tau biomarkers

• Parkinson’s Disease — α-synuclein, neurofilament light

• Amyotrophic Lateral Sclerosis — NfL, neurofilament markers

• Frontotemporal Dementia — CSF biomarkers for FTD subtypes

• Multiple System Atrophy — α-synuclein RT-QuIC

• Progressive Supranuclear Palsy — Tau biomarkers

• Tau Protein — p-tau181, p-tau217, p-tau231

• Alpha-Synuclein — CSF α-synuclein species

• Neurofilament Light Chain — NfL as biomarker

• Beta-Amyloid — Aβ42/Aβ40 ratio

• TREM2 — Soluble TREM2 in CSF

Overview

flowchart TD
    biomarkers_csf_biomarkers_neur["Cerebrospinal Fluid CSF Biomarkers Overview"]
    biomarkers_csf_biomarkers_neur["Cerebrospinal"]
    biomarkers_csf_biomarkers_neur -->|"related to"| biomarkers_csf_biomarkers_neur
    style biomarkers_csf_biomarkers_neur fill:#81c784,stroke:#333,color:#000
    biomarkers_csf_biomarkers_neur["Fluid"]
    biomarkers_csf_biomarkers_neur -->|"related to"| biomarkers_csf_biomarkers_neur
    style biomarkers_csf_biomarkers_neur fill:#81c784,stroke:#333,color:#000
    biomarkers_csf_biomarkers_neur["Introduction"]
    biomarkers_csf_biomarkers_neur -->|"related to"| biomarkers_csf_biomarkers_neur
    style biomarkers_csf_biomarkers_neur fill:#81c784,stroke:#333,color:#000
    biomarkers_csf_biomarkers_neur["biomarker"]
    biomarkers_csf_biomarkers_neur -->|"related to"| biomarkers_csf_biomarkers_neur
    style biomarkers_csf_biomarkers_neur fill:#81c784,stroke:#333,color:#000
    style biomarkers_csf_biomarkers_neur fill:#4fc3f7,stroke:#333,color:#000

Cerebrospinal Fluid (CSF) biomarkers provide direct access to the central nervous system, offering unparalleled insight into neurodegenerative disease pathology. CSF surrounds the brain and spinal cord, making it an ideal matrix for detecting proteins, metabolites, and molecules released by neurons and glia. The analysis of CSF biomarkers has become essential for:

• Diagnosis: Supporting clinical diagnosis of neurodegenerative diseases

• Progression: Monitoring disease progression

• Clinical Trials: Enriching patient selection and measuring treatment response

Core CSF Biomarker Categories

1. Amyloid Pathology Markers

Pathological basis: Aβ42, the most aggregation-prone form, is deposited in amyloid plaques, leading to reduced CSF levels.

2. Tau Pathology Markers

Pathological basis: Neurofibrillary tangles contain hyperphosphorylated tau, which is released into CSF when neurons degenerate.

3. Neurodegeneration Markers

4. Synaptic Markers

5. Neuroinflammation Markers

Disease-Specific Biomarker Profiles

Alzheimer’s Disease (AD)

Core biomarker profile:

• Aβ42: ↓ (reflects plaque deposition)

• Aβ42/40 ratio: ↓

• Total tau: ↑ (reflects neuronal loss)

• p-tau181/217/231: ↑ (reflects tau pathology)

Supporting biomarkers:

• Neurogranin: ↑ (synaptic loss)

• NfL: ↑ (disease progression)

• YKL-40: ↑ (neuroinflammation)

Interpretation framework (AT(N) classification):

• A: Amyloid (Aβ42, Aβ42/40 ratio)

• T: Tau (p-tau)

• (N): Neurodegeneration (t-tau, NfL)

Parkinson’s Disease (PD)

Typical profile:

• Total α-syn: ↓ (in intracellular inclusions)

• α-syn oligomers: ↑ (pathological forms)

• α-syn seeding assays: Positive (RT-QuIC)

• NfL: ↑ (disease progression)

• UCHL1: ↑ (dopaminergic degeneration)

Differential from atypical parkinsonism:

• MSA: Higher NfL, different α-syn pattern

• PSP: Higher NfL, normal α-syn

Amyotrophic Lateral Sclerosis (ALS)

Typical profile:

• NfL: ↑↑ (highly elevated)

• pNfH: ↑ (axon-specific)

• TDP-43: ↑ (proteinopathy)

• IL-6: ↑ (inflammation)

• CHIT1: ↑ (microglia)

Prognostic value: Higher NfL correlates with faster progression and shorter survival.

Frontotemporal Dementia (FTD)

Subtype-specific patterns:

• Semantic variant: Often TDP-43 Type C

• Behavioral variant: Variable (TDP-43 or tau)

• CBD/PSP: Tau pathology

• ALS-FTD: TDP-43 + elevated NfL

Multiple System Atrophy (MSA)

Characteristic profile:

• α-synuclein: RT-QuIC positive (80-90%)

• NfL: ↑ (more elevated than PD)

• Total tau: May be elevated

Preanalytical Considerations

Collection

1. Timing: Morning LP preferred (reduces diurnal variation)

2. Needle: 20-22 gauge

3. Tubes: Polypropylene (low protein binding)

4. Sequence: Discard first 2-3 mL (blood contamination)

Processing

Standardization

• ADNI protocol: Widely adopted reference

• FDA recommendations: For clinical trials

• Reference ranges: Method-specific (Elecsys, Lumipulse, Simoa)

CSF Biomarker Panel: Detailed Reference Ranges and Interpretation

Core Biomarker Reference Ranges

The following table provides reference ranges for the key CSF biomarkers used in neurodegenerative disease diagnosis and monitoring. Values are method-dependent; consult your laboratory’s specific reference intervals.

Note: Reference ranges vary by assay platform (Lumipulse, Elecsys, Simoa). Always use platform-specific cutoffs.

Interpretation Matrix by Disease

Alzheimer’s Disease (AD)

Parkinson’s Disease (PD) / DLB

Atypical Parkinsonism (PSP, CBS, MSA)

ALS/FTD Spectrum

Clinical Utility of Individual Biomarkers

Total Tau (t-tau)

Clinical Utility:

• General neurodegeneration marker: Reflects axonal damage and neuronal loss

• Prognostic indicator: Higher levels correlate with faster disease progression

• Treatment monitoring: Changes may reflect response to neuroprotective therapies

Interpretation Guidelines:

• Mild elevation (300-450 pg/mL): May indicate early neurodegeneration or vascular changes

• Moderate elevation (450-800 pg/mL): Common in AD, vascular dementia

• Severe elevation (>1000 pg/mL): Consider Creutzfeldt-Jakob disease, severe brain injury

Phospho-tau181

Clinical Utility:

• AD-specific marker: More specific than total tau for Alzheimer’s pathology

• Diagnostic accuracy: AUC 0.85-0.95 for AD vs. non-AD

• Disease staging: Levels correlate with Braak stage and cognitive impairment

Interpretation Guidelines:

• Elevated p-tau181 with normal Aβ42: May indicate primary age-related tauopathy (PART) or aging-related tau astrogliopathy (ARTAG)

• Elevated p-tau181 with elevated p-tau217: Strong AD signature

Phospho-tau217

Clinical Utility:

• Highest diagnostic accuracy: Some studies show AUC >0.95 for AD detection

• Early detection: Can identify amyloid pathology before clinical symptoms

• Treatment monitoring: Sensitive to anti-amyloid therapy effects

Interpretation Guidelines:

• p-tau217 >70 pg/mL: High specificity for AD pathology

• p-tau217/Aβ42 ratio: Improves discrimination of AD from other dementias

• Longitudinal monitoring: >10% change over 6 months may be clinically meaningful

Neurofilament Light Chain (NfL)

Clinical Utility:

• Cross-disease neurodegeneration marker: Elevated in virtually all neurodegenerative conditions

• Prognostic value: Strong predictor of disease progression and survival in ALS, FTD

• Trial endpoint: FDA-accepted surrogate endpoint in tofersen trial for SOD1-ALS

Interpretation Guidelines:

• Age-adjusted cutoffs recommended (NfL increases with age)

• Rapidly rising NfL: Aggressive disease course

• Stable/declining NfL: May indicate treatment response

Glial Fibrillary Acidic Protein (GFAP)

Clinical Utility:

• Astrocyte activation marker: Reflects astrocytic response to CNS injury

• AD early detection: Elevated in preclinical and prodromal AD

• Disease progression: Levels increase with disease severity

Interpretation Guidelines:

• GFAP elevated with normal p-tau: Consider astrogliosis from other causes

• GFAP + p-tau217 elevated: Typical AD profile

• GFAP more sensitive than NfL in early AD stages

Alpha-Synuclein RT-QuIC

Clinical Utility:

• Definitive synucleinopathy diagnosis: Detects misfolded α-synuclein aggregates

• High sensitivity: 80-90% in MSA, 85-95% in PD/DLB

• Differential diagnosis: Helps distinguish PD from atypical parkinsonism

Interpretation Guidelines:

• Positive RT-QuIC: Supports diagnosis of PD, DLB, or MSA

• Negative RT-QuIC: Does not rule out synucleinopathy (10-20% false negative)

• Different seeding kinetics may distinguish disease subtypes

Integrated Biomarker Panel Interpretation Algorithm

Step 1: Establish AD Biomarker Profile
├── Aβ42/40 < 0.06 → Amyloid-positive
├── Aβ42/40 ≥ 0.08 → Amyloid-negative
└── Borderline (0.06-0.08) → Consider repeat or complementary testing

Step 2: Assess Tau Pathology
├── p-tau181 > 80 pg/mL → Tau-positive (AD-type)
├── p-tau217 > 70 pg/mL → Confirms AD tauopathy
└── Normal p-tau → Consider non-AD tauopathy

Step 3: Evaluate Neurodegeneration Severity
├── NfL > 800 pg/mL → Advanced neurodegeneration
├── NfL 560-800 pg/mL → Moderate neurodegeneration
└── NfL < 560 pg/mL → Early/mild neurodegeneration (age-adjusted)

Step 4: Assess Astrocyte Activation
├── GFAP > 25 ng/mL → Reactive astrogliosis
└── GFAP normal → Minimal astrocyte involvement

Step 5: Evaluate Alpha-Synuclein Pathology (if parkinsonism present)
├── RT-QuIC positive → Synucleinopathy (PD/DLB/MSA)
└── RT-QuIC negative → Consider tauopathy (PSP/CBS)

Treatment Response Monitoring

Expected Biomarker Changes with Disease-Modifying Therapy

Biomarker Panel Cost and Accessibility

Clinical Implementation

Diagnostic Algorithm

Patient with cognitive/motor symptoms
              ↓
Lumbar puncture for CSF collection
              ↓
Analyze core biomarkers (Aβ42, t-tau, p-tau181)
              ↓
AT(N) classification
              ↓
Integration with clinical assessment
              ↓
Diagnosis

Biomarker Interpretation

Future Directions

Blood-Based Biomarkers

Emerging technologies enabling blood testing:

• Simoa: Ultra-sensitive detection

• Mass spectrometry: Precise quantification

• Expected: Equivalent performance to CSF

Multimodal Panels

Integration of multiple biomarkers:

• Proteomics

• Metabolomics

• Lipidomics

• Extracellular vesicles

Digital Biomarkers

• Continuous monitoring

• Wearable integration

• Real-time assessment

Pre-analytical Considerations

Sample Collection Procedures

Proper CSF collection is critical for accurate biomarker measurements:

Lumbar Puncture Technique

• Patient positioned in lateral decubitus or sitting position

• L3-L4 or L4-L5 intervertebral space identified

• Sterile technique with local anesthesia

• CSF collected via gravity flow into polypropylene tubes^{10CSF collection standardization2010 · J Alzheimers Dis · PMID 20178961Open reference}

Collection Volume

• Standard collection: 10-20 mL total

• First 1-2 mL may contain blood contamination

• Minimum volume for full biomarker panel: 5-6 mL^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}0

Tube Selection and Processing

Preferred Materials

• Polypropylene tubes (low protein binding)

• Avoid glass tubes (protein adsorption)

• Siliconized tubes for special applications^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}1

Processing Timeline

• Centrifuge within 2 hours of collection

• Centrifugation: 2000 × g, 15 minutes, 4°C

• Aliquot into 0.5-1 mL portions

• Store at -80°C immediately^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}2

Freeze-Thaw Considerations

• Maximum 3 freeze-thaw cycles recommended

• Avoid repeated freezing

• Store in small aliquots to minimize thawing^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}3

Analytical Considerations

Platform Comparison

Quality Control

Internal QC

• Run in duplicate or triplicate

• Include known control samples per run

• Monitor coefficient of variation (<10%)^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}4

External Quality Assessment

• Participate in BIOMARKAPD program

• Compare with reference laboratories

• Standardize across centers^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}5

Clinical Interpretation

Biomarker Profiles by Disease

Alzheimer’s Disease (AD)

Parkinson’s Disease (PD)

Frontotemporal Dementia (FTD)

Amyotrophic Lateral Sclerosis (ALS)

Biomarker Combinations

AD Core Biomarker Panel

• Aβ42/40 + p-tau + t-tau (AT(N) classification)

• Sensitivity: 85-95% for AD dementia^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}6

• Specificity: 80-90% vs. non-AD dementia^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}7

Tauopathy Panel

• p-tau181 + p-tau217 + p-tau231

• Differential between AD and non-AD tauopathies^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}8

Neurodegeneration Panel

• t-tau + NfL + neurofilament medium

• General neurodegeneration assessment^{2CSF and blood biomarkers for neurodegenerative diseases2021 · Nat Rev Neurol · PMID 34875237Open reference}9

Disease-Specific Applications

Alzheimer’s Disease

Diagnostic Utility

• Detects amyloid pathology 15-20 years before symptoms

• Differentiates AD from other dementias

• Identifies prodromal AD (MCI)^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}0

Prognostic Applications

• Predicts progression from MCI to AD

• Estimates rate of cognitive decline

• Guides treatment planning^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}1

Treatment Monitoring

• Tracks biological response to anti-amyloid therapy

• Monitors disease modification

• Informs treatment decisions^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}2

Parkinson’s Disease and DLB

Diagnostic Utility

• Supports clinical diagnosis

• Differentiates PD from atypical parkinsonism

• Identifies prodromal disease^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}3

Prognostic Applications

• Predicts cognitive decline in PD

• Identifies rapid progressors

• Guides disease management^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}4

Multiple System Atrophy (MSA)

Characteristic Biomarkers

• Elevated NfL (higher than PD)

• Reduced α-synuclein in CSF

• May show elevated p-tau^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}5

Progressive Supranuclear Palsy (PSP)

Characteristic Biomarkers

• Elevated NfL

• Elevated p-tau181

• Normal Aβ42/40^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}6

Creutzfeldt-Jakob Disease (CJD)

Diagnostic Markers

• Dramatically elevated t-tau (>5000 pg/mL)

• Elevated 14-3-3 protein

• Rapid disease progression marker^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}7

Technical Advances

Automated Platforms

Lumipulse G Series

• FDA cleared for clinical use

• Fully automated, high throughput

• Excellent precision (CV <5%)^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}8

Cobas E (Roche)

• Elecsys CSF panel

• CE-marked, wide adoption

• Standardized across laboratories^{3CSF biomarkers for Parkinson's disease2020 · Mov Disord · PMID 32844781Open reference}9

Novel Assays

Phospho-tau Assays

• p-tau217: Highest diagnostic accuracy for AD^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}0

• p-tau231: Early detection, disease staging^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}1

• p-tau205: Research use^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}2

Multiplex Platforms

• Simultaneous measurement of multiple biomarkers

• Reduces sample volume requirements

• Enables comprehensive profiling^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}3

Integration with Other Biomarkers

Neuroimaging Integration

MRI Correlation

• CSF biomarkers correlate with hippocampal atrophy

• NfL correlates with cortical thinning

• p-tau predicts regional atrophy patterns^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}4

PET Correlation

• Aβ42/40 correlates with amyloid PET SUVr^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}5

• p-tau correlates with tau PET burden^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}6

• Helps interpret imaging findings^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}7

Blood-Based Biomarker Integration

Complementary Information

• Plasma NfL correlates with CSF NfL^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}8

• Plasma p-tau equivalents to CSF p-tau^{4CSF NfL in ALS2022 · Neurology · PMID 35472269Open reference}9

• Blood tests enable frequent monitoring^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}0

Clinical Workflow

• Blood screen first, CSF for confirmation

• Blood for monitoring, CSF for diagnosis^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}1

• Reduces invasive procedures^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}2

Special Populations

Pediatric Populations

Reference Ranges

• Age-specific normal values established^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}3

• Higher baseline levels in children

• Important for pediatric neurological disorders^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}4

Geriatric Populations

Considerations

• Adjust interpretation for age^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}5

• Comorbidities affect levels

• Polypharmacy considerations^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}6

Patients with Comorbidities

Common Complicating Factors

• Vascular disease affects t-tau^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}7

• Depression may influence biomarkers^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}8

• Normal pressure hydrocephalus^{5Biomarkers for FTD subtypes2021 · Lancet Neurol · PMID 34148328Open reference}9

Regulatory and Reimbursement Status

FDA Clearances

Insurance Coverage

• Medicare covers lumbar puncture in specific scenarios

• Private coverage varies by indication

• Self-pay options available^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}0

Cost and Accessibility

Testing Costs

Global Accessibility

• Reference laboratories offer testing

• Shipping protocols established

• International quality assessment programs^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}1

Emerging Research Directions

Novel Biomarkers

Synaptic Markers

• Neurogranin: Synaptic loss marker^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}2

• SNAP-25: Presynaptic marker^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}3

• Synaptotagmin: Synaptic vesicle protein^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}4

Inflammatory Markers

• YKL-40: Astrocyte activation^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}5

• IL-6, IL-1β: Neuroinflammation^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}6

• TREM2: Microglial activation^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}7

Genetic Markers

• CSF AB42/40 response to APOE^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}8

• Genetic risk scores^{6CSF α-synuclein seeding assays2023 · Nat Rev Neurol · PMID 36871059Open reference}9

Technology Development

Point-of-Care Testing

• Rapid CSF testing devices in development^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}0

• Fingerstick blood collection^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}1

• Home collection kits^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}2

Artificial Intelligence

• Machine learning for pattern recognition^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}3

• Multimodal integration^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}4

• Personalized risk prediction^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}5

Limitations and Challenges

Analytical Limitations

• Platform-specific reference ranges

• Pre-analytical variability

• Limited standardization^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}6

Clinical Limitations

• Invasive sample collection

• Cannot determine disease stage precisely

• Some biomarker changes non-specific^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}7

Access Limitations

• Specialized laboratory requirements

• Cost barriers

• Geographic disparities^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}8

Future Directions

Precision Medicine Applications

• Disease subtype-specific profiles

• Individualized biomarker thresholds

• Integrated multi-omic approaches^{7Blood p-tau217 equivalent to CSF2020 · Nat Med · PMID 32877938Open reference}9

Population Screening

• Asymptomatic screening protocols

• Public health implementation

• Ethical frameworks^{8CSF biomarker standardization2021 · Alzheimers Dement · PMID 34596552Open reference}0

Therapeutic Development

• Biomarker-driven clinical trials

• Surrogate endpoints

• Personalized treatment selection^{8CSF biomarker standardization2021 · Alzheimers Dement · PMID 34596552Open reference}1

Allen Brain Atlas Resources

• Allen Brain Atlas - Gene Expression - Search for gene expression data across brain regions

• Allen Brain Atlas - Cell Types - Explore neuronal cell type taxonomy

See Also

• Alzheimer’s Disease

• Parkinson’s Disease

External Links

• PubMed

• KEGG Pathways