One of the anticancer mechanisms of metformin is predicated upon the alteration of the equilibrium between the activation of adenosine monophosphate-activated protein kinase and the inhibition of the mammalian target of rapamycin, which can lead to the negative regulation of HIF-1α and vascular endothelial growth factor, thus ameliorating tumor hypoxia [27]. The gene discussed is VEGFA; the disease is neoplasm.