In the hippocampus of db/db mice, cleaved caspase-3 and Bax were up-regulated, while Bcl-2 down-regulated and the Bcl-2/Bax ratio reduced in comparison to db/m mice; and the number of TUNEL-positive cells elevated both in the hippocampus of patients with T2DM and db/db mice comparison to controls, indicating enhanced apoptosis by the disorder, similar to previous report [34]. This evidence concerns the gene BCL2 and type 2 diabetes mellitus.