Disruption of the mitochondria-associated membranes (MAMs) structure in insulin resistance (IR) and type 2 diabetes mellitus (T2DM) patients results in downregulation of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression, inhibiting mitochondrial biogenesis. The gene discussed is PPARGC1A; the disease is diabetes mellitus.