PDCD1 and nasopharyngeal carcinoma: Our data also showed that CTLA4, LAG3, and HAVCR2 were upregulated EBV DNA Sero- CD8+ T cells, while PDCD1, TIGHT, and ENTPD1 were upregulated in EBV DNA Sero- CD8+ T cells, which further supports the rationale of individualized immunotherapy targeting on NPC with different EBV DNA seropositivity status.