TRIM21 and infection: Therefore, groups of mice were retro-orbitally injected with 50 μg TRIM21-plasmids or vector-plasmids using in vivo-Jet PEI reagent 2 days before and 1 day after CVB3 infection (Figure 5B), and susceptibility to CVB3 myocarditis as well as viral replication were evaluated in a course of 7 days infection.