MAPT and tauopathy: A positive relationship between levels of microglial reactivity and tau-mediated pathogenesis has been characterized in the brains of both human patients and mouse models of tauopathy (Serrano-Pozo et al., 2011, reviews: Barron et al., 2017; Leyns and Holtzman, 2017; Laurent et al., 2018; Perea et al., 2018).