RYR2 and Alzheimer disease: Increasing evidence suggests that the expression and function of RyR2 are upregulated in animal models of familial AD (FAD) and in human AD patients (Kelliher et al., 1999; Smith et al., 2005; Bruno et al., 2012; Oules et al., 2012; Chakroborty and Stutzmann, 2014; Lacampagne et al., 2017; SanMartin et al., 2017; Stutzmann, 2021).