IFI44 and infection: Our data showed that ISGs such as Mx1, Ifit2, Ifit3, Apobec1, Ifi44, and Rsad2 were significantly induced from 2 dpi following infection by the enveloped virus SARS-CoV-2 with lesser induction of IFNs, and the elevated transcription of ISGs was maintained until 7 dpi, which might be related with gradual decrease of SARS-CoV-2 in the respiratory tract.