Presence of IL-1β and TNF-α during HUVEC/M coculture. HUVEC (2 × 10⁵/well) and M (4 × 10⁵/well) were incubated together for 4 hours at 37°C. At the end of incubation the cells were washed, the supernatant was collected, and the presence of IL-1β and TNF-α was assessed by ELISA assay, as specified by the manufacturers (Amersham), while the cells were treated for TF activity assay as described in Materials and Methods. Bars represent the mean of five experiments ± SEM. **P < .01, *P < .05, and °P < .05 (by Wilcoxon rank-sum test) versus HUVEC and M cultured alone.