Northern blot analysis of cytokine-induced DAF on HUVECs and DMECs. ECs were cultured for 6 hours in plain medium alone or supplemented with a combination of TNF- (10 ng/mL) and IFN-γ (500 U/mL). Total RNA was isolated and Northern blots were prepared. Lane 1, unstimulated DMECs; lane 2, TNF- and IFN-γ–stimulated DMECs; lane 3, unstimulated HUVECs; lane 4, TNF- and INF-γ–stimulated HUVECs. The ethidium bromide–stained gel confirmed equal loading of RNA in each lane. These findings were confirmed in 3 separate experiments.