RAB5B and polycystic ovary syndrome: Hypomethylation of LHCGR was linked to increased expression, driving excess androgen secretion in non-obese PCOS patients. Hypermethylation of INSR correlated with reduced expression, contributing to IR in obese PCOS patients. Methylation changes in RAB5B suggest a role in altered insulin signaling and inflammation in PCOS.