The major focus of Mackman lab is the procoagulant protein tissue factor. This is the primary cellular initiator of blood coagulation. We study its role in hemostasis, thrombosis, inflammation, ischemia-reperfusion injury and tumor growth. We have generated a number of mouse models expressing different levels of both mouse and human tissue factor. These mice have been used to provide new insights into the role of tissue factor in hemostasis and thrombosis. In 2007, we developed a new assay to measure levels of microparticle tissue factor in plasma. We found that elevated levels of microparticle tissue factor are associated with venous thromboembolism in cancer patients.