Encoded within the miR-17–92 cluster, miR-20 has been shown to modulate the TGF-β pathway, the E2F transcription family (E2F1-3), the insulin gene enhancer protein (Isl-1), the T-box 1 protein (Tbx1) reviewed by Mogilyansky and Rigoutsos (60); all of which have been linked to PCOS pathophysiology (61). This evidence concerns the gene TGFB1 and polycystic ovary syndrome.