In conclusion, this study reinforces the role of plasma NfL and GFAP in the pre-diagnostic phase of neurodegenerative disease, highlighting distinct profiles and trajectories across various disorders and suggesting that these biomarkers may provide information on which disease is the subject at risk for; moreover, their combined may help identify individuals at higher risk of incident neurodegeneration. The gene discussed is GFAP; the disease is neurodegenerative disease.