According to the common terminology criteria for adverse events by the World Health Organization and National Cancer Institute, anemia is categorized into 5 grades from mild (Hemoglobin (Hb) 10 g/dL – lower limit of normal), to moderate (Hb 8.0 – 9.9 g/dL), severe (Hb <8 g/dL) and life-threatening with urgent interventions indicated (grade 4) or even death (grade 5) (11). Here, GSTM1 is linked to anemia (phenotype).