The "classical" signalling pathway of RAS, when angiotensin II (AngII) is being formed by the help of angiotensin converting enzyme (ACE) and its affinity to the membrane-bound receptors (angiotensin II type 1 and 2 receptors (AT1R and AT2R)), is now being challenged by the discovery of "alternative" pathways with enzymes and receptors, making the picture more diverse.