CD8A and head and neck squamous cell carcinoma: GZMB+PD-1+CD8+ TILs and Ki67+PD-1+CD8+ TILs in “Infiltrating” HNSCC were comparable to those in “Pushing” HNSCC, suggesting that in the “Infiltrating” subset, tumour-specific PD-1+CD8+ TILs maintained the ability to secrete tumour-killing cytokine and to proliferate in the tumour-immune interacting zone (Supplementary Fig. S8b).