Dear Editor,rnEpstein-Barr virus (EBV,also termed human herpesvirus-4) was the first identified human tumor virus.Since its discovery in 1964,studies have shown that EBV infects over 90％ of all people by the time they are adults (Williams and Crawford 2006).EBV infection can result in mucocutaneous and systemic diseases,ranging from self-limited illnesses to aggressive malignancies,including B cell Hodgkin lymphoma and nasopharyngeal carcinoma.