Purpose To investigate the effect of MYD88 gene overexpression on the proliferation and apoptosis of human diffuse large B cell lymphoma(DLBCL)cells,and to prelimi-narily explore the mechanism of MYD88 gene action.Methods PEGFP-C2-MYD88 overexpressing MYD88 L265P gene was transfected into DLBCL cells by plasmid transfection.The exper-iment was divided into blank control group,negative control group and MYD88 L265P overexpression group.The fluores-cence expression of MYD88 L265P after overexpression was ob-served under inverted fluorescence microscope.RT-PCR and Western blot were used to detect the mRNA and protein expres-sion of MYD88 L265P,IRAK4,NF-κB and BCL2 in DLBCL cells before and after overexpression of MYD88 L265.CCK8 method was used to detect DLBCL cells proliferation and Ho-echst staining was used to detect DLBCL cells apoptosis.Re-sults After overexpression of MYD88 L265P,compared with the blank control group(0.670 4±0.017 5)and the negative control group(0.715 3±0.019 6),the MYD88L265P overex-pression group(1.157 2±0.010 2)increased significantly,with statistical significance(all P＜0.05).After overexpression of MYD88 L265P,compared with the blank control group(0.69 ±0.04)and the negative control group(0.81±0.07),the MYD88L265P overexpression group(0.48±0.05)was signifi-cantly decreased,with statistical significance(all P＜0.05).After overexpression of MYD88 L265P,compared with the blank control group(mRNA:1.0158±0.0115,0.987 3±0.010 2,1.007 6±0.015 3,protein:0.183 4±0.058 9,0.096 8± 0.015 7,0.147 5±0.0418)and negative control group(mR-NA:0.9132±0.0098,1.0032±0.0156,0.9327± 0.011 2,protein:0.187 9±0.042 3,0.088 9±0.0513,0.134 8±0.050 1),the mRNA(3.243 2±0.013 6,2.976 6 ±0.0213,1.585 9±0.019 8)and protein expressions(0.452 7±0.052 4,0.218 9±0.047 5,0.301 4±0.059 8)of IRAK4,NF-κB and anti-apoptosis protein BCL2 in MYD88L265P overexpression group were significantly increased,which was statistically significant(all P＜0.05).Conclusion After overexpression of MYD88 L265P,the apoptosis rate of DLBCL cells decreased and the cell proliferation rate increased.The mechanism may be related to the mutation of MYD88 L265P gene,activation and amplification of NF-κB pathway,and pro-motion of the overexpression of antiapoptotic protein BCL2.