GSTM1 and Iron deficiency anemia: The exact Hb A2 concentration could be calculated by integrating both of the split peaks of HbA2, generating a HbA2 concentration of 2.3% in S1, 2.9% in S2, and 3.1% in S3 for CE, which was the level usually observed in a group of normal individuals (2.5–3.5%) [1] but not in a group with heterozygous Hb E without concomitant iron deficiency or α-thalassemia; the Hb A2 concentration normally observed in such a group was 3.8–3.9% [26], the accepted range for diagnosing the β-thalassemia trait.