PNPLA2 and type 2 diabetes mellitus: Indeed, pharmacological or genetical suppression of PNPLA2 in beta cells impairs GSIS.6–9 Interestingly, beta cell lipolysis is upregulated by glucose, and this process is disrupted in human islets affected by T2D, raising the possibility that impaired lipolysis contributes to impaired GSIS in T2D.6 However, how glucose increases lipolysis in pancreatic beta cells is unknown.