RAB5B and polycystic ovary syndrome: LHCGR was overexpressed in non-obese PCOS women, correlating with reduced methylation; INSR was underexpressed in obese PCOS women, correlating with increased methylation; RAB5B was underexpressed in PCOS and had increased methylation at specific CpG sites. Findings suggest different genetic and epigenetic mechanisms driving PCOS in obese and non-obese women.