ICAM1 and influenza: When fluorescently labeled primary human peripheral blood mononuclear cells (PBMCs) were flowed through the endothelium-lined vascular channel 24 hpi with influenza H3N2, we detected upregulation of ICAM1 and TNF in the endothelial cells by qPCR, indicating endothelial inflammation (Supplementary Fig. 6d).