TREM2 and tauopathy: In these same mice, when assessing their microglial gene expression profiles, there was a significant upregulation of proinflammatory genes, such as Clec7a, Tgm1, Olfr110, and triggering receptor expressed on myeloid cells 2 (Trem2), in 9-month-old tauopathy mice expressing human ApoE4 (45).