Virtually every organ system in the human body seems to possess a local renin–angiotensin system (RAS). Most of these systems are independently regulated and compartmentalized from the plasma circulation. In this Review, Velez focuses on the kidney RAS, which is of critical importance for the regulation of blood pressure and salt balance. The article integrates the traditional understanding of the intrarenal RAS with the emerging role of novel players in the system, and the potential implications of these factors in the mechanisms of tissue injury in progressive chronic kidney diseases.
