USP25 and influenza: Beyond this observation, deletion of ubiquitin-specific peptidase 25 (USP25), which has antiviral functions in influenza and herpes infections51, resulted in essentially complete elimination of viral replication without impacting cell growth, suggesting that human USP25 is required by SARS-CoV-2 (Fig. 4d, Extended Data Fig. 4f,g and Supplementary Table 10).