MEG3 and polycystic ovary syndrome: To our knowledge, this is the first study of the targeting relationship between ovarian granulosa cell MEG3 and miR-21-3p in a rat model of PCOS, highlighting the importance of MEG3, miR-21-3p and granulosa cell apoptosis, especially ovarian granulosa cell MEG3, in the treatment of abnormal follicular development in PCOS by acupuncture.