Platelets are cells that augment blood coagulation to form blood clots which in some cases can restrict or halt oxygenated blood flow to the heart and the brain, causing a heart attack or stroke. Although drugs like aspirin have an anticoagulant effect that can decrease the chance and severity of a stroke or heart attack, these drugs do not entirely eliminate the risk. Platelets release mini-versions of themselves, called platelet microparticles (PMPs), into circulation, which are not affected by anti-coagulant drugs. The presence of PMPs in blood is a predictor of future blockages in the brain or heart, but their precise role is not clear. Hon Leong is investigating whether PMPs have the same clotting abilities as platelets to determine whether they cause the blood clots that lead to a stroke or heart attack. Hon is examining the structure of platelet microparticles and their ability to bind to other cells and clots. The results potentially may be used to develop more accurate blood tests to predict and detect strokes and heart attacks and, ultimately, new therapies that prevent platelets and PMPs from producing harmful clots.