In HNSCC, as well as gastric and urogenital cancer, higher numbers of TAM are associated with poor outcomes.10 Studies have also found that an increase in circulating T regulatory (Treg) cells is associated with poor prognosis in HNSCC patients, while infiltration of CD8+ T-cells in the tumor is associated with better local control.11,12,13 How the tumor microbiome affects these associations is under-explored. Here, CD8A is linked to head and neck squamous cell carcinoma.