MAPT and tauopathy: To investigate the link between microglial activation and tau pathology, the tauopathy mouse model PS19 with TREM2 KO was examined (Leyns et al., 2017), demonstrating a reduction of brain atrophy and a decrease in DAM-associated markers, APOE and Cst7, and tau-induced neurodegeneration by the lack of TREM2.