 This is a phase IBII trial to examine feasibility and safety of checkpoint blockade aPD1 with or without aCTLA4 neoadjuvant to standard of care SOC in advanced stage head and neck squamous cell carcinoma HNSCC, a patient population in need for improved clinical outcome and in tumors likely to respond to neoadjuvant aPD1 and aCTLA4. In addition, with this research protocol the potential impact of intratumoral hypoxia on tumor infiltrating lymphocyte TIL abundance, differentiation and effector function will be assessed, and the potentially divergent effects of T cell checkpoint blockade in areas of hypoxia and normoxia. 