MAPT and Schnyder corneal dystrophy: When stratified by diagnosis, CSF Aβ42 was not correlated to PC 3 in the Alzheimer’s disease group, and the correlation between PC 3 and p-tau181, t-tau, and Aβ42/40 in the SCD group was non-significant or only weak (Fig. 4B, Supplementary Table 3B).