After all pairwise combinations of the 12 SNPs were tested, only CYP2J2-rs76271683 and CYP2C8-rs11572177 exhibited significant epistatic effects on GDM susceptibility in all subjects (PInteraction = 0.014, ORInteraction = 0.61, 95%CI 0.41–0.90) [Suppl.Table 5]. Here, CYP2C8 is linked to gestational diabetes.