Hb levels tended to decrease as hepcidin levels increased when TSAT <20% and ferritin >40 μg/L (Hb = −0.14±0.08, p = 0.06), but the relation was reversed in patients with absolute iron deficiency, defined by TSAT <20% and ferritin <40 μg/L (Hb = 0.30±0.14, p = 0.04). The gene discussed is GSTM1; the disease is Iron deficiency anemia.