PRDM9 and nasopharyngeal carcinoma: Genetically, NPC shows relatively few recurrent somatic point mutations or copy number alterations.[4] In contrast, epigenetic aberrations (e.g., DNA methylation) have been frequently reported in NPC.[5] Histone methylation is a critical determinant of chromatin states and a key marker of transcriptional gene regulation.[6] This modification can be dynamically regulated by histone methyltransferases (writers), demethylases (erasers), and methylation reader proteins.