The immunofluorescence assay showed that TRIM21 was localized in cytoplasm and CVB3 infection enhanced its expression at protein and RNA levels (Figures 1E,F).Therefore, our result demonstrate that cardiac TRIM21 expression is up-regulated by CVB3 infection, which may be involved in the regulation of CVB3 infection and the progression of viral myocarditis. Here, TRIM21 is linked to viral myocarditis.