IRS1 and polycystic ovary syndrome: Given the key clinical features of PCOS, initial candidate genes included those implicated in steroidogenesis (e.g. CYP11A1, CYP17A1, STAR), androgen and gonadotropin signaling (e.g. FSHR, LHCGR, SHBG, AR), and insulin resistance (e.g. INSR, INS-VNTR, IGF1, IGF1R, IRS1, PPARG), among others (Urbanek et al. 1999).