YTHDC2 and nasopharyngeal carcinoma: In contrast, 5-azacytidine, a DNA methyltransferase inhibitor, apparently enhanced the protein and mRNA levels of YTHDC2 in both CNE2 and HK1 cells (Figure 5D), which implied that the lower methylation level in the YTHDC2 promoter in radioresistant NPC cells was responsible for high levels of YTHDC2.