DDAH1 and nasopharyngeal carcinoma: Wild‐type EGFR is activated through binding to extracellular ligands.[23] To investigate whether DDAH1 enhances EGFR dimerization and activates the EGFR‐JAK2‐STAT3 pathway through extracellular ligands, we treated DDAH1‐overexpressing NPC cells with nimotuzumab to block the binding of extracellular ligands to EGFR.