APOE and Alzheimer disease: Cao et al., 2021 established a mechanistic link between APOE4 genotype-specific alterations in brain miR-195 expression and AD-related phenotypes, including phospholipid dysregulation, cognitive deficits, lysosomal dysfunction, and tau pathology. The authors demonstrated that miR-195 rescued APOE4-induced cognitive deficits in APOE4+/+ mouse hippocampal tissue and cultured neurons, as well as lysosomal defects in iPSC-derived brain cells from APOE4+/+ AD subjects.