This lecture will focus on how molecules of the extracellular matrix (ECM) impact vascular biology. This is a very important questions since vascular abnormalities (i.e. too many, too few, or abnormal development) are associated with at least 70 different human diseases including heart disease and cancer, which are the two biggest killers in America. Blood vessels are principally composed of endothelial, mural, and smooth muscle cells and all these cell types are very sensitive to the surrounding extracellular matrix. In fact, some of the most potent regulators of vascular function are components of the vascular extracellular matrix. However, our understanding of how blood vessels are influenced by the ECM is limited by out incomplete understanding of molecules in the vascular ECM and how these EMC molecules impact cell biology.