Elevated levels of COX-2 have been detected in EBV-induced NPC and LCLs, and Gandhi J. et al. observed that EBV reactivation in LCLs and BL cell lines occurred through activation of the COX-2/PGE2 pathway [107], supporting an autocrine positive regulatory loop in which Zta induces COX-2 expression and COX-2 further promotes a constitutive level of BZLF1 transcription and viral reactivation. Here, PTGS2 is linked to nasopharyngeal carcinoma.