This hypothesis has the potential to be tested clinically by studying the effect of aggressive correction of anemia in AS patients, perhaps using vWf multimers and/or TGF-β1 levels as biomarkers.PerspectivesCOMPETENCY IN MEDICAL KNOWLEDGE: AS leads to increased shear force, which in turn leads to cleavage of high molecular weight vWf multimers, which in turn leads to a bleeding diathesis, gastrointestinal bleeding, and anemia (Heyde’s syndrome). This evidence concerns the gene TGFB1 and anemia (phenotype).