In recent years, new members of RAS, such as angiotensin-converting enzyme 2 (ACE2), angiotensin-(1–7) [Ang-(1–7)], Mas receptor (MasR), angiotensin-(1–9) [Ang-(1–9)] and angiotensin IV (Ang IV), in the treatment of heart failure have received an increasing attention, and research work in our and other laboratories have discovered that ACE2-Ang-(1–7)-MasR, as a new axis of RAS, played a crucial role in the treatment of cardiovascular diseases7. Here, ACE2 is linked to heart failure.