Mas, which was protooncogene, first detected in vivo by tumorigenic properties originating from rearrangement of its 5'-flanking region was identified as a functional receptor for angiotensin (1-7) and provide a clear molecular basis for the physiological actions of this biologically active peptide. Angiotensin (1-7) is mainly produced from angiotensin II by angiotensin converting enzyme 2, homologue of angiotensin converting enzyme. Many investigations suggested angiotensin (1-7) via Mas receptor might play protective effects on hypertensive complications, such as renal dysfunction and cardiovascular diseases, competed with angiotensin II and its type 1 receptor.