“…12 HSCT recipients have several identifiable risk factors for thrombosis including malignancy, high-dose myeloablative chemotherapy and immune-modulatory drugs, [13][14][15][16] graft versus host disease (GVHD), [17][18][19] infections, 14,20 indwelling vascular catheters and prolonged immobilization. 14 HSCT is also associated with an 'acquired hypercoagulable state' characterized by inflammation, endothelial damage and activation of endothelium-dependent coagulation factors, increase in von Willebrand factor and platelet adhesion, increased thrombin generation, decreased anti-thrombin levels and decreased levels of anticoagulant proteins such as protein C. [21][22][23][24][25][26][27] graft versus host disease (GVHD) is associated with inflammation that leads to endothelial damage and activation. 28 TNF alpha, an essential mediator in the pathogenesis of GVHD, has been shown to enhance pro-thrombotic alterations on the endothelial cell surface.…”