The opposite, abnormal P‐tau181 and GFAP with normal NfL results was less common (total cohort: 3%; SCD + MCI set: 7%), but this result is highly indicative of Aβ+ (total cohort: 90% Aβ+; SCD + MCI set: 75% Aβ+). This evidence concerns the gene GFAP and Schnyder corneal dystrophy.