AIF1 and type 1 diabetes mellitus: The TREM2/Iba1 ratio, which reflects the level of TREM2 in individual microglia, was significantly higher in the prefrontal cortex of the T1D group compared to the Ctrl group at both 8 and 15 weeks (Ctrl vs. 8 W: p = 0.0242, Ctrl vs. 15 W: p = 0.0107, Fig. 4i).