JUN and nasopharyngeal carcinoma: A study using NPC cell lines demonstrated that the YYD domain at COOH-terminal activation region 2 (CTAR2) of LMP1 is critical to activate the JNK signaling pathway leading to phosphorylation of c-Jun to form an AP-1 complex with c-Jun (homodimer) or c-Fox (heterodimer) to bind to the promoter region of DNMT1 and enhance the DNMT1 expression (44).