To determine whether these cytokines are similarly responsible for endothelial suppression of COUP-TF2 during influenza infection, we treated immortalized human lung microvascular ECs (iMVECs) (29) with either IL-1β or TNF-α for 24 hours and confirmed that both cytokines down-regulate COUP-TF2 in iMVECs at both the mRNA and protein level (Fig. 4, A and B). Here, IL1B is linked to influenza.