In detail, the mechanism of host cell infection is the same for SARS-CoV and SARS-CoV2, i.e., it depends on the external protein of the virus, the glycoprotein (S) spike, which is able to bind and recognize the human receptor angiotensin converting enzyme 2 (ACE2), primed by the transmembrane protease, serine 2 (TMPRSS2) and/or extracellular matrix metalloproteinase inducer CD147 [2,6,7,8]. The gene discussed is ACE2; the disease is infection.