Like other SARS-CoVs [16], including SARS-CoVs isolated from bats [17], the human SARS-CoV-2 uses angiotensin-converting enzyme 2 proteins (ACE2) as an entry receptor on mammalian cells; in particular, SARS-CoV-2 is capable to infect HeLa cells heterologously expressing ACE2 of human and of different mammals like civets, pigs and mice, demonstrating infection versatility of SARS-CoV-2 to different hosts [1]. The gene discussed is ACE2; the disease is infection.