In this study, we document that: (1) Significantly shortened PFS and EFS after R-CHOP chemotherapy was observed in the patients with NAD(P)H oxidase subunits (NCF4 rs1883112) GG genotype; (2) ATP-binding cassette transporters (ABCG2 rs231137) may predict PFS and EFS; (3) Elder (>60 years old) or male patients with GG genotype of rs2231137 displayed poor PFS and EFS comparing with A allele; (4) NADPH RAC2 rs13058338 (AT) and CD20 rs2070770 (CC) were independent predictors of chemotherapy-induced toxicity of DLBCL patients. Here, FMO5 is linked to diffuse large B-cell lymphoma.