Of note, it has recently been demonstrated that ID is common in patients with coronary artery disease with concomitant type 2 diabetes mellitus and independently predicts poor outcome.9 Heart failure patients with renal dysfunction are prone to develop ID, which often coincides with low-Hb level.24 Therapy with i.v. iron is able to correct these ominous abnormalities. The gene discussed is GSTM1; the disease is diabetes mellitus.