Modulation of the renin-angiotensin system, in particular of the function of the hormones angiotensin II and angiotensine-(1-7), is an important target for pharmacotherapy in the cardiovascular system. In the classical view, such modulation affects cardiovascular cells to decrease hypertrophy, fibrosis, and endothelial dysfunction, and improves diuresis. In this view, excessive stimulation of angiotensin II type 1 receptors fulfills a detrimental role, as it promotes cardiovascular pathogenesis, and this is opposed by stimulation of angiotensin II type 2 and the angiotensin-(1-7) receptor coded by the Mas proto-oncogene. In recent years, this view has been broadened with the observation that the renin-angiotensin system regulates bone marrow stromal cells and stem cells, thus involving hematopoiesis and tissue regeneration by progenitor cells. This change of paradigm has enlarged the field of perspectives for therapeutic application of existing as well as newly developed medicines that alter angiotensin signaling, and now stretches beyond cardiovascular therapy. In the present lecture the role of angiotensin II and angiotensin-(1-7) and their respective receptors in hematopoietic and mesenchymal stem cells is reviewed and the latest findings with respect to Ang-(1-7) are discussed as well as possible pharmacotherapeutical implications.