CD44 and nasopharyngeal carcinoma: In CD44 + NPC cancer stem cells (CSCs), BMI1 knockdown attenuates self-renewal, proliferation, migration, and invasion, while concurrently enhancing chemosensitivity to cisplatin and 5-fluorouracil through reactivation of the p16INK4a-p14ARF-p53 tumor suppressor axis [26].