〔Abstract〕 Objective To explore the effect of interferon regulatory factor 2 binding protein ( IRF2BP2) on the proliferation of 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 Western 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 downstream 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 targets of the IRF2BP2 protein, and the corresponding binding signals were visualized using the Integrated Genomics Viewer (IGV). ResultsCompared 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, knocking out IRF2BP2resulted in significant enrichment of differential genes in MYC-related signaling pathways, and the protein expression levels of pathway molecules MYC, CDK4, and 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 affects the cell cycle and proliferation of AML cells by targeting and regulating MYC.