ADAMTS13 and thrombotic thrombocytopenic purpura: A lack of ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 - also known as von Willebrand factor-cleaving protease), a protease responsible for degrading von Willebrand factor precursors, can cause severe cases of TTP-HUS [4].