Since chemotherapeutic agents induce PD-L1 expression on NPC cells, and IFNβ has previously been shown to induce PD-1 expression on NK cells [16], our next aim was to establish the contribution of the PD-L1/PD-1 checkpoint to the killing of NPC cells exposed to chemotherapeutics by activated NK cells. This evidence concerns the gene PDCD1 and nasopharyngeal carcinoma.