It was found that cisplatin, 5-fluorouracil and gemcitabine for the treatment of nasopharyngeal carcinoma caused upregulation of PD-1 in NKs and PD-L1 in nasopharyngeal carcinoma cells through activation of the nuclear factor-κB (NF-κB) pathway, resulting in suppression of the killing ability of NK cells. Here, CD274 is linked to nasopharyngeal carcinoma.