Several growth factors and their receptors, such as platelet-derived growth factor (PDGF)/PDGFR, vascular endothelial growth factor (VEGF)/VEGFR, fibroblast growth factor (FGF)/FGFR, stem cell factor (SCF)/c-Kit, glial cell line-derived neurotrophic factor (GDNF)-family ligands/rearranged during transfection (RET), and angiopoietin/Tie22,111, regulate the growth, differentiation and migration of cancer cells and angiogenic activities of vascular endothelial cells22,111. This evidence concerns the gene RET and cancer.