CD44 and nasopharyngeal carcinoma: The study on NPC with positive EBV cell line C666-1 showed that CD44+ cancer stem cells have the capacity to self-renew, differentiate, initiate tumor cells invivo, and they are highly resistant to 5-fluorouracil therapy.8 Ebstein-Barr virus can potentially induced CSCs in EBV-positive NPC by altering the Notch and hedgehog signaling pathways through thelatent membrane protein-1 (LMP1), LMP2A.9,10