CD8A and nasopharyngeal carcinoma: Among the CD8+ T-1, CD8+ T-2 and CD8+ T-3 subtypes, high expression of cytokines and effector molecules was exhibited in CD8+ T-1, followed by CD8+ T-2 and CD8+ T-3 (Fig. 4c), suggesting that CD8+ T-1 represented the main cytotoxic population in NPC.