FLT4 and cancer: The approach for targeting the VEGF-C/VEGF-D/VEGFR-3 pathway that has been most extensively employed in animal models of cancer, but is yet to be tested in the clinic, is the use of soluble versions of VEGFR-3 that bind VEGF-C and VEGF-D, thereby inhibiting activation of endogenous VEGFR-3 (see previous section) (He et al, 2002; Krishnan et al, 2003; Lin et al, 2005).