CYP19A1 and polycystic ovary syndrome: The widely used animal models of PCOS include the androgen model (10, 11), estrogen model (12, 13), aromatase inhibitor model (14, 15) and combined models, such as the dehydroepiandrosterone (DHEA) plus high fat diet (HFD)-induced mouse model (16), high-fat high-sugar (HFHS)-induced mouse model (17, 18), etc. Although a variety of PCOS animal models have been established for research purposes, there is still disagreement which model best recapitulates the disease (19, 20).