Soluble FasL release by HUVECs. Supernatant samples were obtained from cultures of HUVECs incubated for 16 hours with or without 1–100 μM H2O2. The amount of soluble FasL in the samples was determined by ELISA. Data are reported as the means ± SEM of values obtained from 5 experiments. *p < 0.05 vs. cells not exposed to H2O2.