Due to the clinical relevance of PD-14, TIM-340, and LAG3-targeting41 therapies currently being used or tested, we validated the PD-L1, galectin-9, and HLA-DR expression at the protein level and corroborated that myeloid population are the major contributors to the ICL expression in the HNSCC TME. This evidence concerns the gene CD274 and head and neck squamous cell carcinoma.