Nevertheless, our initial literature searching did not reveal sufficient eligible publications to support quantitative analyses for any polymorphic loci of other cytokines, which include IL-1, IL-2, IL-4, IL-8, IL-12 and IL-18, so we only explored associations with the risk of GDM for TNF-α, IL-6 and IL-10 polymorphisms in our quantitative analyses. Here, IL2 is linked to gestational diabetes.