More recently, it has been shown that the age-associated decrease in p16INK4a expression in pancreatic islets could be related to the decreased expression of BMI1 (132) and EZH2 (133), two chromatin-regulating polycomb group proteins, indicating the crucial role that epigenetic regulation could play in the control of cell cycle progression of beta cells in both aging and type 2 diabetes (134). Here, CDKN2A is linked to type 2 diabetes mellitus.