Dr. Bray's laboratory studies the role of platelets in cardiovascular disease, and disorders of bleeding and excessive blood clotting. His major areas of investigation include: (1) The role of platelets in arterial thrombosis, with the identification and functional characterization of platelet risk factors and their impact on cardiovascular therapy. He studies how genetic variations in platelet adhesive molecules affect both the clinical and platelet phenotypes. (2) Identification of novel genes and gene products involved in platelet reactivity using genome scan and platelet RNA expression array approaches. (3) Studies on gender differences and hormonal effects on platelet function and thrombosis. (4) Pharmacogenetic studies: a) testing for interactions between candidate genes and hormone therapy using DNA samples from the participants in the Women's Health Initiative, and b) candidate gene and genome-wide scan approaches for determining genes that regulate the platelet response to aspirin.