TNF and influenza: Although TNFR1 has been reported at low levels on CD8 T cells [6] and TNFR1 is involved in T cell proliferation in allogeneic models [35,36] we focused here on TNFR2/TNF interactions, as TNFR2 was the predominant receptor detected on the CD8 T cells in the influenza infected mice (Figure 1F).