A major interest in the inflammatory functions of platelets led to the description of bactericidal and complement activating proteins in platelets, and later to an interest in platelet-endothelial interactions and the physiology of human vascular endothelial cells. Dr. Weksler was the first to observe that endothelial cells were a major source of the protective prostaglandin, prostacyclin. During the last decade, her interest has focused on the effects of xenobiotics and in particular tobacco smoke on endothelial function. Dr. Weksler has developed several immortalized lines of human and mouse microvascular endothelial cells which have been used by scientists all over the world as models for the exploration of endothelial interaction with blood precursors, tumor cells, inflammatory factors and leukocytes. Recently she has created a immortalized line of normal human brain endothelial cells as a model of the blood brain barrier, the first successful all human model of this important structure.