FOXP3 and head and neck squamous cell carcinoma: Spatial distribution imaging analysis (multiplex immunofluorescence) suggested that a small fraction of CD8+PD-1+ T cells are also GITR+ (FoxP3–) within inflamed and excluded compartments of HNSCC, including the tumor, stroma and tumor-proximal lymph node aggregates (Fig. 2e and Extended Data Fig. 2c).