The NCI grading of anemia is defined as follows: “mild (Grade 1), Hb from 10 g/dL to the lower normal limit; moderate (Grade 2), Hb 8.0–9.9 g/dL; severe (Grade 3), Hb <8 g/dL to 6.5 g/dl; life-threatening (Grade 4), Hb <6.5 g/dL”2. The gene discussed is GSTM1; the disease is anemia (phenotype).