Some mechanisms of IR in women with PCOS are connected to an excessive activity of 17 α-hydroxylase, which regulates the conversion of 17-hydroxyprogesterone into androstenedione, excessive stimulation of IGF-I receptors, and diminished synthesis of insulin-like growth factor binding protein 1 (IGF-BP1) [52]. This evidence concerns the gene IGFBPL1 and polycystic ovary syndrome.