It can be assumed that the increased expression of the CTH, ANPEP, and G6PD genes in T2D samples compared with non-diabetic ones appear to be adaptive and aimed at replenishing glutathione deficiency in beta cells of diabetics: CTH and ANPEP supply amino acids such as L-cysteine (CTH and ANPEP) and glycine (ANPEP) for de novo biosynthesis of GSH, whereas G6PD generates NADPH for the reduction of GSSG to GSH. This evidence concerns the gene CTH and type 2 diabetes mellitus.