USP1 and infection: The results showed that the expression of USP1 mRNA levels was significantly up-regulated 24 h after infection with all four influenza viruses-A/PR/8/34 (H1 N1), A/Texas/50/2012 (H3 N2), B/Colorado/06/2017 (BV), and B/Phuket/3073/2013 (BY) (Fig. 1A-C).