We measured a large set of endothelial cell biomarkers [31, 32] pointing at enhanced activation (higher sVCAM-1, von Willebrand factor, s-thrombomodulin and TFPI levels), more disturbed glycocalyx integrity (higher syndecan levels) and reduced endothelial barrier function (higher angiopoietin 2 levels) in patients with hyperferritinemia. The gene discussed is SDC1; the disease is isolated hyperferritinemia.