Endometrial hyperplasia, with enlarged endometrial glands with cystic dilatations, was shown in a PCOS model induced by letrozole in hamsters, with increased antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT), and altered metabolic parameters, such as increased leptin and insulin and decreased insulin receptor and glucose transporter 4 [22]. The gene discussed is CAT; the disease is polycystic ovary syndrome.