Recent data from pre-clinical and clinical studies suggest that metformin may have additional benefits beyond its glucose-lowering effects, including potential anticancer properties, including the activation of AMPK, the inhibition of the mammalian target of rapamycin (mTOR) signaling pathway, direct effects on cancer cells, the inhibition of gluconeogenesis, a reduction in insulin levels, a reduction in inflammation, and the modulation of the immune system. This evidence concerns the gene INS and cancer.