The renin-angiotensin system has been implicated in vascular function and disease. Angiotensin-converting enzyme and angiotensin II are believed to be the most important components. However, alternative factors, such as angiotensin-I/II-(1-7) and chymase, have also been shown to be of significance in animal models. In this paper, we review some facts and provide additional proof for the functional significance of angiotensin-I/II-(1-7) and chymase in humans.