CD8A and influenza: Intra cellular cytokine staining revealed that the majority of CD8 influenza specific T cells in the BAL secreted IFNγ and TNF (39.9%), followed by IFNγ only producers (35.7%) and 14.5% produced all three cytokines (IFNγ, TNF, and IL-2), while CD4 T cells produced mainly IFNγ (49.3%) (Figure 4B).