SQSTM1 and nasopharyngeal carcinoma: To investigate whether the three proteins (RAN, SQSTM1, TRIM29) serve as biomarkers for predicting NPC metastasis, immunohistochemistry was performed to detect the expressional levels of the three proteins in an cohort of formalin-fixed and paraffin-embedded archival tissue specimens including metastatic and non-metastatic NPCs.