CD8A and head and neck squamous cell carcinoma: Similarly, in non-small cell lung cancer and head and neck squamous cell carcinoma (HNSCC) patients, TCF1+ stem-like CD8 + T cells are most likely located in tertiary lymphoid structures (TLSs), which are organized aggregates of immune cells that form within nonlymphoid tissues, not in the tumor parenchyma21,36.