To study the differentiated expression of the proto-oncogene Pokemon in nasopharyngeal carcinoma (NPC)cell lines and tissues, mRNA and protein expression levels of CNE1, CNE2, CNE3 and C666-1 were detectedseparately by reverse transcription polymerase chain reaction (RT-PCR), real-time PCR and Western-blotting.The immortalized nasopharyngeal epithelial cell line NP69 was used as a control. The Pokemon protein expressionlevel in biopsy specimens from chronic rhinitis patients and undifferentiated non keratinizing NPC patientswas determined by Western-blotting and arranged from high to low: C666-1>CNE1>CNE2> CNE3>NP69. ThePokemon mRNA expression level was also arranged from high to low: CNE1>CNE2>NP69>C666-1>CNE3.Pokemon expression of NP69 and C666-1 obviously varied from mRNA to protein. The Pokemon protein levelof NPC biopsy specimens was obviously higher than in chronic rhinitis. The data suggest that high Pokemonprotein expression is closely associated with undifferentiated non-keratinizing NPC and may provide usefulinformation for NPC molecular target therapy.