There were 866 (21.1%) mild anemia patients (100 mg/L ≤ Hb < 130 mg/L for men and 100 mg/L ≤ Hb < 120 mg/L for women) and 80 (1.9%) moderate-severe anemia patients (Hb < 100 mg/L). Here, GSTM1 is linked to anemia (phenotype).