Only 3 of the DCB/Flu mice (n = 6) had detectable levels of TNFα at 6 dpi (Additional file 1). Tregs (CD4+, CD25+, and Foxp3+) cells were quantified following EPFR exposure and influenza infection at 4 and 6 dpi using flow cytometry. Here, FOXP3 is linked to influenza.