Literature search was done by PubMed7 using the key words “breast cancer polymorphism phase I,” “breast cancer polymorphism phase II,” “breast cancer polymorphism CYP” “breast cancer polymorphism UGT,” “breast cancer polymorphism SULT,” “breast cancer polymorphism GST,” and “breast cancer polymorphism NAT” in August 2012. The gene discussed is SLC35A2; the disease is breast carcinoma.