TREM2 and type 2 diabetes mellitus: We found that the expression of Nlrp3, Cmklr1, compared with db/dm group, the number of positive cells labeled by TREM2 and Iba-1 in hippocampus of db/db group was significantly increased (Figure 4), suggesting that T2DM facilitates microglial activation and increases levels of inflammatory factors in the hippocampus.