The results indicate that WNK1 pathway inhibitors exhibit stronger antitumor activity than the VEGFR inhibitor PTK787 in the xenotransplantation assay, although this result might be simply due to the different efficacy of these inhibitors, another possibility is that WNK kinases might also promote tumor cell proliferation autonomously within the cancer cells, we will examine the role of WNK kinases using endothelial-specific wnk1 overexpression transgenic fish (Section 2.8). This evidence concerns the gene KDR and cancer.