In vascular adventitia, the outermost connective tissue covering the vessel, adventitial fibroblasts produce collagen to provide structural support. Human Aortic Fibroblasts are the first cells of the vascular wall to respond to hypertension and vascular injury. During pathological conditions, HAF produce cytokines and chemokines to induce mass infiltration of immune cells into the adventitial layer of the vessel wall. Immune cell infiltration into the adventitia results in adventitial inflammation and can lead to cardiovascular disease. The important properties of HAF make them an ideal tool for studying the pathogenesis of cardiovascular disease. But they are also valuable tools for the development of novel disease treatments.