Differences in TME content of regulatory immune cells (i.e., Foxp3+CD4+ Tregs and myeloid-derived suppressor cells) or tumor-intrinsic immune suppression mechanisms were not accounted for in these analyses and could therefore serve as potential mechanisms underlying the divergence in the immune cell interactions operating in the TME of HNSCC compared with that of CRC. Here, CD4 is linked to head and neck squamous cell carcinoma.