CD4 and influenza: One of these cytokines is the multipotent Interferon gamma (IFN-γ) which plays a key role in the development of innate and adaptive immune response [24–27] and is widely accepted as a marker of the adaptive immune response IFN-γ is produced by CD4+ Th1 cells, most CD8+ cells, and NK cells, is known to be an important contributor to antiviral immunity to influenza [28] and is able to control viral infection and induce inflammatory damage [29].