HSPA5 and infection: To further elucidate the role of ER stress in the development of viral myocarditis, CVB3-infected mice were treated with 100 mg/kg ER stress inhibitor tauroursodeoxycholic acid (TUDCA) or 2 mg/kg activator tunicamycin (Tm) at day 1 and day 4 post infection, and the expression of GRP78 and GRP94 in mice heart tissue were detected by real-time PCR (Fig. 1F,G), and then the changes in myocarditis severity were determined.