Figure 4. Forrest plot of the relationship between TNFα -308A/G polymorphism and risk of PsV, a–b, Pooled lower risk of PsV with TNFα -308A/G polymorphism; c–d, In Caucasian and Asian subgroups, pooled lower risk of PsV with TNFα -308A/G polymorphism; e, Pooled lower risk of type I PsV with TNFα -308A/G polymorphism; f, no risk of type ΠPsV with TNFα -308A/G polymorphism.