Both insulin and IGF‐1 can induce the activation of specific oncogenic pathways including the phosphoinositide 3‐kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) and the mitogen‐activated protein kinase (MAPK) pathways [99, 100], which have multiple effects on cancer progression such as promoting obesity‐associated hepatic tumorigenesis [58]. This evidence concerns the gene MTOR and obesity due to melanocortin 4 receptor deficiency.