In order to facilitate viral replication, IRE1-XBP1 pathway that mediates IRE1α RNase activity was suppressed in infection by the Hepatitis C virus, human cytomegalovirus, and Rotavirus while activated in infections of Influenza A virus, Murine coronavirus mouse hepatitis virus, Hepatitis B virus, Japanese encephalitis virus, Flavivirus, and Epstein-Barr virus [7,23,24,25,26,57,58,59,60], indicating that the roles of IRE1α-XBP1 on viral replication depend on viruses. This evidence concerns the gene ERN1 and infection.