CYP19A1 and polycystic ovary syndrome: Studies have shown that aberrant methylation of several genes such as microsomal epoxide hydrolase (1EPHX1) [14], follistatin (FST) [15], hypermethylation of aromatase (CYP19A1) [16], and hypomethylation of Yes-associated protein 1 (YAP1) [17] are associated with PCOS pathogenesis.