The SARS-CoV-2 attachment mechanism (panel A) is as follows: The S protein binds ACE-2, allowing entry into the host cell and infection; ACE converts angiotensin I to angiotensin II; Angiotensin II exerts biological functions through AT1R and AT2R, leading to severe vasoconstriction in organs; ACE-2 hydrolyzes angiotensin II to the vasodilator angiotensin 1-7, which binds to the Mas receptor and has a protective function in several organs. This evidence concerns the gene ACE2 and infection.