VWF and thrombotic thrombocytopenic purpura: In the 1980s, Moake et al. observed the occurrence of platelet attractive ultra-large vWF (ULvWF) multimers in the plasma of relapsing TTP patients, prompting the hypothesis that patients with TTP likely lacked a depolymerase-like enzyme, that if present, would restrict the length of circulating ULvWF [3].