PSEN1 and familial Alzheimer disease: Fibroblasts from FAD patients with PS1 mutations presented increased expression of the autophagy-lysosomal markers LC3II, LAMP2 and cathepsin D, increased total GSK3 levels and enhanced ERK1/2 (Thr202/Tyr204) and tau (Thr231, Ser396/Ser404) phosphorylation.