In the endometrium of PCOS patients, a study of 15 endometrium of PCOS patients showed that the mRNA expression levels of ACE2, AT1, AT2 and Mas receptors in the endometrium of PCOS patients were higher than those in the control groups (73), These results make it clear that the elevated expression level of RAS components may affect the development of endometrium and play a role in its pathological process. This evidence concerns the gene ACE2 and polycystic ovary syndrome.