Ongoing studies are investigating other potential immune implications and combinations of cancer-related pathways beyond PD-1 or EGFR An active, not recruiting study aims to investigate the clinical and biological effects of the therapy R/M HNSCC with atezolizumab, targeting PD-L1, in combination with bevacizumab, mAB against VEGF (trial identifier: NCT03818061). Here, PDCD1 is linked to head and neck squamous cell carcinoma.