RASSF1 and nasopharyngeal carcinoma: The data of in vitro and in vivo indicate that 5-azacytidine, and 5’-aza-2’deoxycytidine greatly restored the expression of RASSF1A. For instance, the NPC cell line C666-1, which was confirmed to be completely methylated and with no expression of RASSF1A, was administrated with 5’-aza-2’deoxycytidine.