Liu et al. (2021) found an interesting phenomenon: ACE2 of ferret and mink, which exhibit limited binding affinity with viral S1 protein, have the function of mediating the entry of SARS-CoV-2 in cell-level analysis. However, farm minks developed fatal infections, which constitutes a model of severe and potentially lethal infection of SARS-CoV-2 (Oreshkova et al., 2020). The gene discussed is ACE2; the disease is infection.