CDKN2A and type 2 diabetes mellitus: In humans, increased expression of p16 mRNA in peripheral blood T lymphocytes (PBTL) is associated with well-established pro-aging exposures such as tobacco use, physical inactivity, chemotherapy, and radiation, and genetic alterations in the p16 locus have been associated with aging-related conditions in humans such as frailty, cardiovascular disease and type 2 diabetes [14, 15].