UBE2L3 and systemic lupus erythematosus: A multivariate logistic regression analysis with their interaction term according to a multiplicative model [26] showed a synergistic interaction with the two SNPs (ORint = 1.6, P = 0.0028), indicating a synergistic interaction between TNFAIP3 and UBE2L3 genes in conferring SLE risk.