ADAMTS13 and thrombotic thrombocytopenic purpura: Dysfunctional activation of the VWF/ADAMTS13 system in thrombotic microangiopathies (TMAs) (such as TTP, HUS, and DIC) results in microvessel occlusion by a complex web of VWF-rich thrombi causing tissue hypoperfusion and organ failure, potentially life-threatening [84].