Targeted knockout of representative genes such as KAT7, BRD1, MEAF6, and KAT8 (acetyltransferases); CHUK, IKBKB, and IKBKG (NF-κB); ADSL and GART (purine synthesis); RNF31 and OTULIN (linear ubiquitination); and MDM2 (p53 control) reduced proliferation of NPC cells in vitro relative to normal nasopharyngeal controls, supporting their functional essentiality. This evidence concerns the gene RNF31 and nasopharyngeal carcinoma.