BMI1 and nasopharyngeal carcinoma: As has been reported in the case of NPC, Bmi-1 can increase the mobility of nasopharyngeal epithelial cells and is associated with SLUG and other transcription factors.23 ZEB2 is an important transcription factor among cancers,24 and ZEB1 promotes cancer cell dedifferentiation by repressing master regulators of epithelial polarity.25, 26 Therefore, increased ZEB1 and ZEB2 levels may promote EMT-dependent invasion and cancer stem cell activity, features that are essential for the metastatic spread of cancer.