In support of this concept, Barrès et al. 46 have recently shown that hyper-methylation of the Peroxisome proliferator-activated receptor γ coativator 1 α (PGC1α) promoter modulates PGC1α expression, implying a mechanism for decreased mitochondrial content in skeletal muscle from T2D patients. The gene discussed is PPARGC1A; the disease is type 2 diabetes mellitus.