GBF1 and infection: Infection in the presence of the solvents dimethyl sulfoxide (DMSO) and methanol (MeOH), as well as the known inhibitors of MHV RNA synthesis Brefeldin A (BrefA, inhibitor of GBF1) [60] and MG132 (proteasome inhibitor, probably also affects MHV entry; [61]) were included as controls.