Insulin‐like growth factor‐I (IGF‐I) is a polypeptide hormone that stimulates cell division and inhibits apoptosis; it is through these properties that it is thought to play a role in the development and progression of carcinogenesis.6 Prospective studies have shown that higher circulating concentrations of IGF‐I are associated with a higher risk of cancers at specific sites, including the breast,7 prostate8 and possibly the thyroid.9 Three case–control studies have examined the relationship between circulating IGF‐I concentrations and risk of melanoma, but the results were not consistent. This evidence concerns the gene IGF1 and cancer.