An alternative approach for assessing the role of the VEGF-C/VEGF-D/VEGFR-3 system in cancer metastasis has been to treat well-established animal models of tumour spread, that have not been genetically engineered to express VEGF-C or VEGF-D, with inhibitors of this signalling pathway and to monitor the effects on lymphatic and distant organ metastases. This evidence concerns the gene FLT4 and cancer.