CONFIRM-HF (Ferric CarboxymaltOse evaluatioN on perFormance in patients with IRon deficiency in coMbination with chronic Heart Failure) was a double-blind, multi-center, prospective, randomized, placebo-controlled trial which enrolled 304 ambulatory patients with symptomatic HFrEF, iron deficiency (defined as ferritin < 100  ng/mL, or ferritin 100–300  ng/mL if transferrin saturation < 20%) and haemoglobin < 15  g/dL. The gene discussed is TF; the disease is nutritional disorder.