FLT4 and cancer: A range of reagents to target VEGF-D or components of its signaling pathways has been developed, including neutralizing monoclonal antibodies (Mabs) to VEGF-D [8,89,90] or to VEGFR-3 [91,92,93], and soluble forms of VEGFR-3 [94,95,96,97,98] (Figure 1), that restricted solid tumor growth and/or metastatic spread in animal models of cancer.