ID3 and polycystic ovary syndrome: Among many genes that are involved in cell proliferation, several genes were deregulated in PCOS CCs compared with non-PCOS CCs, including prostaglandin-endoperoxide synthase 2 (PTGS2), tumor necrosis factor-alpha-induced protein 6 (TNFαIP6), TGF-β2, caveolin 1 (CAV1), inhibin, beta B (INHβB), EGFR, and inhibitor of DNA binding 3 (ID3) (Fig. 6A).