PDCD1 and nasopharyngeal carcinoma: In conclusion, we have shown that chemotherapeutics used for the treatment of NPC sensitize NPC cells to killing by NK cells and that this lethal action can be augmented by blockade of the PD-L1/PD-1 checkpoint, which in turn is induced by chemotherapeutics through NF-κB-dependent upregulation of PD-1 in NK cells and PD-L1 in NPC cells.