Vascular disease is a pathological state of large and medium sized muscular arteries and is triggered by endothelial cell dysfunction. Because of factors like pathogens, oxidized LDL particles and other inflammatory stimuli endothelial cells become activated. This leads to change in their characteristics: endothelial cells start to excrete cytokines and chemokines and express adhesion molecules on their surface. This in turn results in recruitment of white blood cells (monocytes and lymphocytes), which can infiltrate the blood vessel wall. Stimulation of smooth muscle cell layer with cytokines produced by endothelial cells and recruited white blood cells causes smooth muscle cells to proliferate and migrate towards the blood vessel lumen. The process causes thickening of the vessel wall, forming a plaque consisting of proliferating smooth muscle cells, macrophages and various types of lymphocytes. This plaque result in obstructed blood flow leading to diminished amounts of oxygen and nutrients that reaches the target organ. In the final stages, the plaque may also rupture causing the formation of clots, and thus leading to heart strokes.