EBV-positive NPC cells are able to secrete cytokines and exosomes that drive the TIME toward immune suppression [79]: data from whole-exome sequencing and single-cell sequencing studies have progressively shown tumor infiltration by dysfunctional and exhausted CD8+ T cells and effector T (Teff) cells that overexpress inhibitory immune checkpoints, such as PD-L1, LAG3, galectin 9–TIM3, TIGIT, and CTLA4; moreover, other immunosuppressive cells, such as Tregs, TAMs-M2, and MDSCs, and various inhibitory cytokines have been identified to contribute to immunosuppression [79]. Here, CTLA4 is linked to neoplasm.