PTGS2 and polycystic ovary syndrome: Although some studies observed decreased COX-2 expression in the endometrium51 and granulosa cells52 of PCOS models, most research supports the overactivation of COX-2 in PCOS patients, especially in ovarian tissue53–55, Which is presumed to be related to hyperandrogenism, increased inflammatory responses, and abnormal follicular development in PCOS patients.