In a mouse model of viral myocarditis, MEG3 expression level is significantly elevated, and downregulation of MEG3 attenuates heart injury by inactivating nuclear factor-kappa B (NF-κB) signaling, decreasing the polarization of M1 macrophages, and elevating the polarization of M2 macrophages [20]. This evidence concerns the gene MEG3 and viral myocarditis.