MAPT and Alzheimer disease: These data are highly significant to AD because: (1) mitochondrial dysfunction (Selfridge et al., 2013) and calpain-activation are linked to AD (Saito et al., 1993; Ferreira and Bigio, 2011); and (2) calpain-dependent Tau fragments are detected in the brains of AD patients (Ferreira and Bigio, 2011; Garg et al., 2011).