ATF2 and infection: After MeV-CKO infection, PKR increases IFNβ production through the activation of p38/activating transcription factor 2 (ATF-2) and c-Jun N-terminal kinase (JNK)/c-Jun mitogen-activated protein kinase (MAPK) signaling axes and NF-κB, all of which participate in the formation of the IFNβ enhanceosome complex [37,45,46,47].