The group could confirm the radiosensitizing effects in further studies when treating the same VEGF-secreting HNSCC model as orthotopic xenografts using alternative, but functionally equivalent agents, namely the anti-VEGF monoclonal antibody bevacizumab combined with the EGFR TKI erlotinib or using the combination of the VEGFR TKI sunitinib and the EGFR mAb cetuximab (45, 46). Here, KDR is linked to head and neck squamous cell carcinoma.