To further investigate the role of the NF-κB pathway in this model, NPC cells and NK cells were incubated with NF-κB-specific siRNA and expression of PD-L1 in NPC cells and PD-1 in NK cells was determined by immunoblot; the efficiency of the siRNA silencing of NF-κB was monitored by flow cytometry (Suppl. The gene discussed is CD274; the disease is nasopharyngeal carcinoma.