In recent years, it has been demonstrated that natriuretic peptides, or compounds with similar activity, decrease the number of several cancer cells in vitro through a reduction of DNA synthesis [32] and inhibition of c-Fos and c-Jun protooncogenes [33], inhibit lung metastases and skin carcinogenesis in animal models [34,35], and diminish the expression of vascular endothelial growth factor and that of its receptor VEGFR2, thus having the potential to control vasculogenesis [36]. Here, KDR is linked to cancer.