In the PCOS ovaries, the important mechanism of suppression of PTEN expression and hyperactivation of the insulin and IGF-1 signaling pathways is an increase in the expression of two microRNAs of miR-200 family, miR-200b and miR-200c, which negatively affect the expression of the PTEN gene [252]. The gene discussed is IGF1; the disease is polycystic ovary syndrome.