In many laboratory mammalian animal models, TBT exposure was associated with reproductive, metabolic, and cardiovascular abnormalities, including hyperandrogenism, cystic ovarian follicles, irregular estrous cycle, elevated levels of LH, obesity, abnormal lipid profiles, glucose metabolism, and insulin resistance similar to those found in polycystic ovarian syndrome (PCOS) in women and animal models of PCOS [22,63,64,65]. The gene discussed is PLOD1; the disease is obesity due to melanocortin 4 receptor deficiency.