NR2F2 and influenza: Notably, we find that deletion of COUP-TF2 in human lung microvascular ECs (iMVECs) (29) in vitro or in EC-specific COUP-TF2 conditional KO mice greatly impairs EC proliferation and, in the latter, results in exaggerated weight loss, strongly decreased capillary oxygen saturation, and increased mortality following influenza infection.