A recent study showed that E2 ubiquitin-conjugating enzyme RAD6 and E3 ligase MDM2 cooperatively promote ASF1A degradation49, thus we envision that downregulation of RAD6 or/and MDM2 could possibly lead to ASF1A upregulation in lung cancer even with less abundance of USP52. This evidence concerns the gene PAN2 and lung carcinoma.