ACE2 is the newest member of the RAAS and shares approximately 40% similarity with the somatic form of ACE [9, 10] . ACE2 is a membrane-bound carboxypeptidase and its cellular and tissue distribution is different from that of ACE. While ACE is expressed in the endothelium throughout the vasculature, ACE2 is distributed in tissues with the most abundant expression in heart, kidney, lung, small intestine, and testis [14] . ACE2 can be released into the circulation and urine by shedding [15] . Tumor necrosis factoralpha-converting enzyme (TACE/ADAM17) is the sheddase responsible for the ectodomain cleavage and shedding of ACE2 [16] .