Angiotensin converting enzyme 2 (ACE2), a dipeptidyl-carboxypeptidase type I integral membrane protein, is considered a therapeutic target for COVID-19 patients.4 Extensive studies have demonstrated that ACE2 is a critical receptor for coronavirus infections, including severe acute respiratory syndrome coronavirus (SARS-CoV) which emerged 17 years ago.5 SARS-CoV attaches to the host ACE2 receptor and then enters target cells by using the virus spike protein. This evidence concerns the gene ACE2 and COVID-19.