For management of ACS and severe anemia (hemoglobin [Hb] 5.8 g/dL; baseline 8.7 g/dL), she received 10 mL/kg (230 mL) of O Rh(D) Neg C + E- K- pRBCs, leukoreduced, CMV seronegative, HbS negative. Here, GSTM1 is linked to anemia (phenotype).