To further characterize the relevance between gene methylation changes and radiosensitivity, we evaluated the differential methylation and expression status of RASSF1A, RPRM, CDKN2A, and 14-3-3σ both in vitro and in vivo in NPC by pyrosequencing and real-time RT-PCR. Here, RASSF1 is linked to nasopharyngeal carcinoma.