Consistent with previous findings, fibrosarcomas lacking VEGF expression6,27 (Supplementary Fig. 7a) grew more slowly than those expressing VEGF when implanted into WT mice (Fig. 7a), due to insufficient angiogenesis (Fig. 7b, e), severe hypoxia (Fig. 7c, f), and apoptosis (Fig. 7d, g). This evidence concerns the gene VEGFA and fibrosarcoma.