The pharmacology of the perioxisome proliferators activated receptor PRAR ligands is summarized. The alpha, delta (beta) and gamma receptors occur in vascular walls and on macrophages suggesting that their ligands can be used to modify atherosclerosis and other forms of vascular disease. Furthermore, gamma-ligands exert an anti-inflammatory effect on macrophages. Troglitazone has been used to protect against glomerulosclerosis in rats. The thiazolidinediones (TZDs) could be important adjunct therapy for lupus glomerulonephritis.