When compared with nondiabetic retinas (Fig. 2A), the bright CD39+ microglia density in the T1D (Fig. 1C) and T2D (Fig. 1E) retinas was decreased significantly (P < 0.05, see Fig. 1H), with no significant difference between T1D and T2D retinas. This evidence concerns the gene ENTPD1 and type 1 diabetes mellitus.