CASP3 and infection: The improved infection outcome observed in VP4-mut infected mice corroborated with lower synthesis of viral proteins, less phosphorylation of ERK1/2 along with lower ERK1/2 levels as well as negligible cleavage of caspase 3 at 7 dpi as compared to wildtype infected mice (Fig. 9f–i; Supplementary Fig. 21a).