Hyperinsulinemia induces a decrease in insulin-like growth factor binding protein-1 and 2 (IGFBP-1 and 2) and reduces sex hormone binding globulin (SHBG) levels, resulting in an increase in free estrogen and androgen and insulin-like growth factor-1 (IGF-1) levels (2). The gene discussed is IGFBP1; the disease is hyperinsulinism.