Day 7 ECFCs were cultured with rhIFNγ (100 U/mL), with or without anti-IFNγ antibody (10 μg/mL) or anti-IgG1 antibody (10 μg/mL) in serum-free medium. After 24 hours of incubation, viability was determined using trypan blue exclusion. Apoptosis was assessed with annexin V using flow cytometry after 16 hours of incubation. The mean ± SD of triplicate studies is shown.

P< .001.