GFAP and Schnyder corneal dystrophy: Moreover, plasma biomarkers, such as amyloid‐β42/40 (Aβ42/40), neurofilament light (NfL), phosphorylated tau181 (p‐tau181), and glial fibrillary acidic protein (GFAP), have been widely used in AD and SCD studies [16, 17, 18, 19, 20].