KDR and neoplasm: The vascular endothelial growth factor receptor (VEGFR) belongs to the RTKs superfamily and mainly comprises fms-like tyrosine kinase-1 (FLT-1, VEGFR1), kinase domain-containing receptor (KDR, VEGFR2) and fms-like tyrosine kinase-4 (FLT4, VEGFR3), which contribute to tumor progression via mediation of tumor angiogenesis and lymphangiogenesis [6,7].