Here, we performed a head-to-head comparison of the diagnostic performance of plasma p-tau181, NfL, and GFAP in AD, FTD, progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), DLB, and a group of cognitively impaired individuals with suspected non-AD physiopathology (SNAP). The gene discussed is GFAP; the disease is Alzheimer disease.