John et al. (2018) observed downregulation of beta cell identity genes, FoxO1, MafA and Nkx6.1, in the db/db murine model of T2D [48], while genetic deletion of FoxO1 in murine beta cells renders these cells more sensitive to metabolic stress, and is associated with upregulation of pluripotency genes such as Ngn3, Oct4, Nanog and L-Myc [49]. This evidence concerns the gene FOXO1 and type 2 diabetes mellitus.