There are strong indications to believe that epigenetic modifications could also be key players in the T2D-related pathways/events as can be seen by the hypermethylation of promoter regions of several genes (INS—encoding insuline, PDX-1—playing an important role in the development of pancreas and in β-cell function, PPARGC1A—participating in the energy homeostasis, GLP1R—regulating insulin secretion) in islets from T2D-donors compared to islets from control subjects [18]. The gene discussed is PPARGC1A; the disease is type 2 diabetes mellitus.