Figure 7a shows dramatic induction of Angpt2 levels at Day9 post-infection. We next tested whether direct stimulation of endothelial cell by IAV would result in Angpt2 release. Stimulation of HPAEC with 1 MOI IAV for 4 h or 24 h did not yield increase in Angpt2 release or synthesis (data not shown). Application of other lung injury-relevant factors shown to stimulate endothelial Angpt2 secretion or expression [28,29,30] gave disparate results in HPAEC. TNFα showed marked and significant suppression of Angpt2 levels in HPAEC and in 24 h conditioned media (Figure 7b,c). This evidence concerns the gene TNF and infection.