Fig. 4. Quantification of soluble VEGF isoforms. Soluble VEGF isoforms (VEGF 120 and VEGF 164) were determined in conditioned medium after either 22 hours hypoxia or normoxia. Bars represent the means ± standard deviations (triplicates from three independent experiments, normalized to protein concentrations). Statistical differences were calculated as: wild-type normoxia vs HIF-1-null normoxia; wild-type hypoxia vs HIF-1-null hypoxia; wild-type normoxia vs wild-type hypoxia. **P0.01.