And both deletional HPFH/δβ thalassemia and δ‐globin gene mutations will complicate routine β‐thalassemia screening (Usually, the electrophoretic testing for β‐thalassemia trait was carried out using the following selection criteria: Hb A2 ≥ 3.5% and/or Hb F ≥2.0%). The gene discussed is GSTM1; the disease is thalassemia.