Blood tests showed worsening of anemia [hemoglobin (Hb) from 8.7g/dL (baseline) to 7.4g/dL], an increased reticulocyte absolute number [from 142 × 109/L (baseline) to 430 × 109/L], and an increased indirect bilirubin level [from 1.4mg/dL (baseline) to 2.3mg/dL]. Here, GSTM1 is linked to anemia (phenotype).