For example, Cai and collaborators [12] have proved a significant downregulation of miR-145 in the isolated human GCs of PCOS women, which has been related to an increase of cell proliferation and DNA transcription by the activation of the insulin receptor substrate 1 (IRS1) and of the downstream MAPK/ERK signaling pathway [12]. The gene discussed is IRS1; the disease is polycystic ovary syndrome.