ESR1 and systemic lupus erythematosus: Consistent with this, ethnicity contributed to the heterogeneity for ESR1 PvuII and ESR1 XbaI. Moreover, sensitivity analysis revealed that the heterogeneity was reduced by removing Johansson et al.’s [31] study, which was the only study in the meta-analysis of the association between ESR1 XbaI polymorphism and SLE susceptibility that was based on Caucasians.