MAPT and Alzheimer disease: A reduction in Iba1 positive microglia was observed in patients with AD using similar microglial markers (Minett et al., 2016), and Iba1 positive dystrophic microglia are present in AD cases (Streit et al., 2009; Tischer et al., 2016), preceding the spread of tau pathology (Streit et al., 2009).