MKI67 and influenza: On IL-4 stimulation, we saw an upregulation of Ki-67 in human CD4 T cells but not NHP cells, much akin to IFNγ stimulation, and high expression of pSTAT3 in the natural killer of IL-4-stimulated blood cells, but not in PBMCs from humans challenged with influenza (Supplementary Fig. 13c).