Figure 1.

Joint effect and additive interaction between EBV variant 163364 and host HLA SNPs on the risk of nasopharyngeal carcinoma

(A) rs2860580, (B) rs2894207, and (C) their joint status. OR, odds ratio; CI, confidence interval; RERI, relative excess risk due to interaction. Two host SNPs were combined as one categorical variable in the models by their joint status, which divided the study subjects into two groups: one group at higher risk carrying only risk alleles of both host SNPs and the other group at lower risk carrying protective alleles of either host SNP.