STAT1 and viral infectious disease: MAPK phosphorylates a large number of substrates and induces the activation of transcription factors such as NF-κB p65, c-Jun and STAT1, which play pivotal roles in regulating the immune response to viral infection and cytokines, and the expression of most chemokines is regulated primarily at the level of transcription through the activation of NF-κB and interferon (IFN) regulatory factors [11].