During viral infection, type I interferons (mainly secreted by infected cells) and type II interferon (interferon-gamma, IFNγ, mainly secreted by T cells) can induce the expression of the MHC-I component genes through the IFNγ-IFNGR-JAK-STAT pathway [26] and facilitate the CD8+ T-cell-dependent infected cell elimination [27]. Here, IFNG is linked to viral infectious disease.