The recent studies have shown that the levels of angiotensin-I-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) in patients with lung adenocarcinoma (LUAD) are significantly increased, and the increased levels of these enzymes are associated with susceptibility of patients with LUAD to SARS-CoV-2 (3), because ACE2 serves as an important binding site for SARS-CoV-2, leading to facilitate viral entry into target host cells (4). The gene discussed is ACE2; the disease is lung adenocarcinoma.