Angiotensin II, a small peptide hormone that plays key roles in the regulation of blood pressure, also contributes to inflammatory processes that promote the development of atherosclerosis. In this issue of Cell, AbdAlla et al. (2004) provide evidence that pathogenic actions of angiotensin II involve covalent crosslinking of angiotensin AT1 receptors by factor XIIIA transglutaminase, resulting in stable receptor dimers with enhanced signaling properties.