Development and validation of diagnostic assays for iron disorders. Projects focus on investigating the circulation state of hepcidin and standardization of hepcidin assays worldwide, which will enable the establishment of reference intervals and clinical decision limits for this measurand. In addition, research includes development of an assay for hepcidin suppressor erythroferrone, functional tests for TMPRSS6 mutations involved in disrupted hepcidin signaling and a test for functional iron deficiency using metabolic fluxes.