〔Abstract〕 To explore the effect of interferon regulatory factor 2 binding protein 2 ( IRF2BP2) on the proliferation of acute myeloid leukemia ( AML) cells and its molecular mechanism．Methods The CRISPR-Cas9 gene editing technology was used to knock out IRF2BP2 in human AML cell lines Kasumi-1 and U937，and West- ern blot was performed to detect the knockout efficiency of IRF2BP2 protein．Cell morphology was observed using a microscope．Cell phenotypes were analyzed by CCK-8 assay，colony formation experiments，and flow cytometry． RNA-Seq was performed to identify differentially expressed genes between the IRF2BP2 knockout group and the control group in the U937 cell line．Gene Set Enrichment Analysis ( GSEA) was conducted to explore the down- stream molecular mechanisms．Western blot was used to detect the expression of downstream differentially expressed genes．The Cleavage Under Targets and Tagmentation ( CUT＆Tag) technique was applied to identify the direct tar- gets of the IRF2BP2 protein，and the corresponding binding signals were visualized using the Integrated Genomics Viewer ( IGV) ．Results Compared with the control group，after knocking out IRF2BP2，the CCK-8 experiment showed that AML cell proliferation was inhibited ( P ＜0. 05) ; the number of colonies in the IRF2BP2 knockout group decreased ( P＜0. 05) ，and the proportion of G1 phase was prolonged ( P＜0. 05) ; in U937 cell lines，knoc- king out IRF2BP2 resulted in significant enrichment of differential genes in myelocytomatosis oncogene ( MYC) -re- lated signaling pathways，and the protein expression levels of pathway molecules MYC，cyclin-dependent kinase 4 ( CDK4) ，and cyclin － dependent kinase 2 ( CDK2 ) decreased with the downregulation of IRF2BP2; using IRF2BP2 antibodies in U937 cell lines for CUT＆Tag experiments，IGV visualization analysis showed a significant increase in signal peaks in the MYC promoter region．Conclusion IRF2BP2 protein affects the cell cycle and pro- liferation of AML cells by targeting and regulating MYC．