APP and Alzheimer disease: Aβ activates the RhoA/ROCK pathway in AD brains, significantly elevating ROCK1, which in turn promotes the rate of phosphorylation of the amyloid precursor protein (APP) phosphorylation by beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), accelerating Aβ production (Henderson et al., 2016; Hu et al., 2019).