PSEN1 and Cognitive impairment: Indeed, transgenic mice given the human presenilin-1 (PS1) gene—which encodes one of the two subunits of γ-secretase—with one missense mutation (Val97Leu, PS1V97L) formed abundant Aβ oligomers (Zhang et al., 2014), produced cognitive deficits, and exhibited cellular oxidative stress markers (Tian et al., 2019; Hou et al., 2018).