HO-1–induced DAF expression is independent of ROS. (A) HUVECs were treated for 48 hours with VEGF (25 ng/mL) or TNF-α (10 ng/mL) and IFN-γ (500 U/mL) (T/I), in the presence or absence of N-acetylcysteine (5 mM) or vehicle alone (UT). DAF expression was measured by flow cytometry using mAb 1H4 and presented as mean RFI plus or minus SEM (n = 2 experiments). (B) HUVECs were left untreated (UT), infected with Adv–HO-1 or empty vector control adenovirus Ad0 (both MOI 200), and surface antigen expression was measured by flow cytometry at 24 hours after infection using mAbs 1H4 (DAF), BRIC 229 (CD59), and TRA-2-10 (MCP). Results are RFI (mean ± SEM; n = 3 experiments). *P < .05.