ATF5 and neoplasm: PRMT1 is responsible for 85% of global arginine methyltransferase activity and catalyzes the formation of H4R3me2a, a histone modification linked to transcriptional activation.[18] It has been implicated in tumor progression by regulating key oncogenic genes.[19] For instance, PRMT1 enhances neuroblastoma cell survival by upregulating ATF5 and drives colorectal cancer progression by upregulating EGFR and TNS4 expression through H4R3me2a.[12f] However, its downstream effectors in HNSCC remain unclear.