FOXO1 and type 2 diabetes mellitus: Xie et al. [35] further showed that Polygonatum sibiricum heteropolysaccharides restore insulin sensitivity by upregulating PI3K and AKT phosphorylation while downregulating forkhead box protein O1 (FoxO1) and glycogen synthase kinase 3β (GSK3β) phosphorylation, thereby reinstating the insulin-mediated PI3K/AKT signaling axis in T2DM mice.