The complex pathophysiology of hyperinsulinemia, i.e. increased serum level of insulin-like growth factor-1 (IGF-1) and leptin and its association with the risk of PMBC has been evaluated previously and discussed extensively (Braun et al. 2011; Vatten et al. 2008; Irvin et al. 2005). The gene discussed is LEP; the disease is hyperinsulinism.