AMP-activated protein kinase (AMPK) is a protein kinase-sensing metabolite and if activated after MI it becomes an endogenous protective signaling mechanism; and pre-administration of metformin (an oral diabetes type 2 medicine) has a cardio-protective role against MI that is mediated via the AMPK-eNOS-mediated signaling cascade [209]. The gene discussed is NOS3; the disease is type 2 diabetes mellitus.