CHUK and nasopharyngeal carcinoma: To identify the key molecules that are essential for NPC cell differentiation, Yan et al. [4] compared three paired RNA libraries from NPC tumors and adjacent non-tumorous tissues, validated their findings by real-time polymerase chain reaction (PCR) and Western blotting assays, and determined that IKKα down-regulation is involved in the undifferentiated status of NPC.