Under an evolutionary view, somatopause, which involves both animals and humans, is a “protective” process against the formation of tumours, due to the removal of GH-mediated stimulation of cell proliferation, including the mitogenic effect by insulin-like growth factor 1 (or IGF-1), and against other chronic degenerative or metabolic diseases (i.e., osteoarthrosis or diabetes mellitus) [3]. The gene discussed is IGF1; the disease is metabolic disease.