The A allele of rs78060119 is assigned no function by CPIC. Patients with the CC genotype and cancer who are treated with fluorouracil, a fluoropyrimidine-based chemotherapy, may have decreased, but not absent, risk and reduced severity of drug toxicity as compared to patients with the AA or AC genotype. However, conflicting evidence has been reported. Other genetic and clinical factors may also influence risk of drug toxicity.