KDR and cancer: VEGFR-2 is a 200–230 kDa molecular weight receptor known as FLK-1 as well as KDR.42 VEGFR-2 is widely acknowledged as the most significant among all three VEGFRs,43 has been extensively studied, and its presence has been firmly confirmed in various types of cancer.44 When VEGF attaches to the extracellular domain, it triggers the activation of tyrosine kinase in the intracellular domain 45.