In our humanized mouse NPC-PDX model, the tumor-infiltrating CD8+ T cells expressed higher levels of PD-1 and CTLA-4, as well as LAG3, and these exhausted phenotypes might hinder the anti-tumor efficacy of ICB by suppressing their cytotoxicity and cytokine-producing capability. The gene discussed is CTLA4; the disease is nasopharyngeal carcinoma.