GSTP1 and nasopharyngeal carcinoma: To attempt replication from a previous report of a 2.6-fold increased risk of NPC among individuals homozygous for TT of CYP2E1-RsaI (rs2031920) variant[8], the tagging SNPs for GSTP1, MPO, and NQO1 (which 100% covered these genes) and four SNPs of CYP2E1 (which covered CYP2E1-RsaI (rs2031920) variant) were genotyped in a second independent cohort of 213 IgA+ NPC cases and 230 IgA+ controls (phase II cohort).