The BioIron group of experts recently provided a clear definition of HC: a genetic condition impairing the hepcidin-ferroportin axis that is caused by the homozygous HFE p.C282Y variant and is associated with elevated transferrin saturation, iron depositions in the liver and clinical manifestations of iron overload in the absence of a red blood disorder (1). The gene discussed is TF; the disease is Tangier disease.