CD274 and nasopharyngeal carcinoma: Data in Table 3 revealed that positive expression of PD-L1 protein was identified as an independent good prognostic factor (P=0.002), while positive expression of p-S6 protein (P=0.003), lymph node metastasis (LNM) status (P=0.004), clinical N category (P<0.001), M category (P< 0.001) and clinical stages (P=0.005) were identified as independent poor prognostic factors for overall survival of NPC patients.