KDR and cancer: On this basis, inhibition of the VEGF-A/VEGFRs signaling represents a widely used approach for cancer treatment through the use of the anti-VEGF-A and anti-VEGFR-2 monoclonal antibodies (mAbs) bevacizumab and ramucirumab, respectively; the chimeric molecule ziv-aflibercept; or a number of multi-targeted small-molecule TK inhibitors [65,66].