SARS-CoV-2, the causative agent of the coronavirus disease 2019 (COVID-19) [1], is an enveloped, single-stranded RNA virus, which mainly enters host cells through its obligate receptor, angiotensin-converting enzyme 2 (ACE2) [2,3,4,5,6,7,8,9]. The gene discussed is ACE2; the disease is COVID-19.