INSR and cancer: In the case of PC, the molecular mechanism by which up-regulated AdipoQ levels inhibit cancer progression is still unclear; possibilities include 1) increasing insulin sensitivity via phosphorylation of insulin receptors, which down-regulates insulin/IGF-1 signaling, 2) down-regulating the expression of inflammatory cytokines that inhibit NF-κB activation, 3) directly activating the AMPK pathway to activate the p53 tumor suppressor gene, and 4) promoting cancer cell apoptosis via peroxisome proliferator-activated receptor gamma (PPARγ) activation and inhibiting angiogenesis [58, 59].