It is suggested that epigenetic modification may contribute to the development of T2DM [41], [42], as DNA methylation alters the expression of different genes like COX7A1, NDUFB6, PGC-1α and PPAR-δ, which are essential to normal mitochondrial function in skeletal muscle tissue [7], [13], [23], [40]. The gene discussed is COX7A1; the disease is type 2 diabetes mellitus.