Among these genes, KHDRBS3 has been previously suggested as a candidate PCOS-associated gene in a Korean study population15; moreover, LHCGR, RAB5B, and TOX3 were reported in a Chinese population12,13 but not in a European population14, suggesting that ethnicity is an important factor in determining PCOS-susceptible loci. Here, RAB5B is linked to polycystic ovary syndrome.