Angiotensin-converting enzyme 2 (ACE2), the cell membrane adapter for SARS-CoV-2, was reported to be an interferon-stimulated gene (ISG), which raised potential risk of using IFN therapy to treat SARS-CoV-2 infection.41 However, latest evidence suggests that IFN induce an isoform of ACE2 not related to SARS-CoV-2 infection.42,43 Considering the complexity of IFN signaling and insufficient knowledge of COVID-19 immunopathogenesis, the therapeutic strategy of IFN should be carefully optimized in future trials. Here, ACE2 is linked to COVID-19.