This is consistent with the finding that autoantibodies that recognize various domains of ADAMTS13 (including those similar to the Wh2-11-1 epitope) result in acquired TTP [26] and the fact that the immunogenicity of clotting factors such as factor VIII is a significant impediment to the treatment of hemophilia [27]. This evidence concerns the gene ADAMTS13 and thrombotic thrombocytopenic purpura.