The dynamic air–liquid interface promotes the differentiation of human airway epithelial cells to highly express the genes ACE2 and TMPRSS2. Moreover, the lung-on-a-chip suggested that only two drugs, amodiaquine, and toremifene, had significant effects on viral entry reduction among the seven approved drugs pre-screened as inhibitors of SARS-CoV-2 S protein infection using a conventional culture of Huh-7 cell lines,118 which are widely used for viral infection screening in vitro. The gene discussed is ACE2; the disease is infection.