METTL14 and polycystic ovary syndrome: CDD was found to reduce the expression of METTL3, METTL14 [151], FTO, ALKBH5 [169], YTHDF1 and YTHDF2 in peripheral blood and ovarian tissues of PCOS rats, as well as the expression of METTL3, FTO and YTHDF1 proteins in ovarian tissues [170] (Fig. 3).