The VEGF receptor tyrosine kinase inhibitor SU11248 [37] blocked both basal and VEGF-induced VEGFR2 and pERK phosphorylation in H5V cells (Figure 8a) and HUVEC (data not shown) but interestingly had no effect on basal levels of pERK1/2 in the fibrosarcomas (Figure 8d). This evidence concerns the gene VEGFA and fibrosarcoma.