Better understanding the prevalence and role of AD in this cohort, and whether AD is detectable with blood biomarkers, would permit rapid identification of the AD in these syndromes, leading to new opportunities to parse contributions from various neuropathologies to clinical presentation.18 Therefore, we investigated whether plasma biomarkers could identify individuals with AD on autopsy in 12 clinical neurodegenerative syndromes associated with either AD or non-AD neuropathology to better understand the clinical value of testing for plasma p-tau217, GFAP, and NfL in these cohorts. The gene discussed is GFAP; the disease is Alzheimer disease.