INS and catecholaminergic polymorphic ventricular tachycardia: In knock-in mouse models where these CPVT-linked mutations leading to RyR2-mediated Ca2+ leak were reconstituted, mitochondrial dysfunction and blunted ATP production with concomitantly increased sarcolemmal KATP channel function (reversible by the KATP blocker glibenclamide) were found in pancreatic β-cells to cause reduced insulin secretion and consequently, IGT (36).