Jamieson et al. demonstrated that NQO2 rs1143684, missense Phe > Leu SNP, related to lower enzyme activity, modulates the adjuvant doxorubicin and cyclophosphamide (AC) efficacy and tamoxifen toxicity in 227 early breast cancer (BC) patients, with estrogen receptor (ER)- and progesterone receptor (PR)-negative disease [53]. The gene discussed is NQO2; the disease is breast cancer.