CD8A and nasopharyngeal carcinoma: In an HPV-associated nasopharyngeal cancer study, it is suggested that PD-1high CD8+ TILs are associated with worse-disease free survival, and that HPV infection status may be a factor to determine the percentage of PD-1high CD8+ TILs in NPC; a higher frequency of PD-1high CD8+TILs with impaired anti-tumour functionality in HPV- tumours was detected when compared to that of HPV+ tumours (24).