本研究旨在探讨FOXO3在胃癌（GC）中的作用。从TCGA和GTEx数据库收集了胃癌和正常组织的数据。采用Kaplan-Meier方法进行生存分析，并使用ENCORI在线分析工具预测潜在的miRNA相互作用。使用MCPCOUNTER和Tumor Immune Dysfunction and Exclusion（TIDE）算法预测了免疫浸润与FOXO3之间的关系。最后，采用基因集富集分析（GSEA）探索了GC发展过程中FOXO3的潜在途径。 我们发现，FOXO3的mRNA表达水平在肿瘤组织中明显高于正常组织，GC患者的差异表达与较高的FOXO3表达相关。我们还发现，hsa-miR-18a-5p和hsa-miR-18b-5p可以与FOXO3相互作用，而高表达的hsa-miR-18a-5p和hsa-miR-18b-5p预示着GC患者的良好预后。TP53突变与高FOXO3表达显著相关，而ARID1A突变与低FOXO3表达相关。多种免疫细胞与FOXO3的表达有关，较低的FOXO3表达可能更适合免疫检查点阻断治疗。 我们发现FOXO3是一个潜在的癌基因，其转录水平与TP53和ARID1A的突变相关。此外，FOXO3可能通过吸附miRNA来影响免疫浸润和不同的信号通路，从而影响胃腺癌患者的预后。

The purpose of this study was to explore the role of FOXO3 in gastric cancer (GC).Data on gastric cancer and normal tissues were collected from the TCGA and GTEx databases. Survival analysis was performed with the Kaplan-Meier method, and the ENCORI online analysis tool was used to predict potential interaction miRNA. The MCPCOUNTER and Tumor Immune Dysfunction and Exclusion (TIDE) algorithm were used to predict the relationship between immune infiltration and FOXO3. Finally, gene set enrichment analysis (GSEA) was used to explore the potential pathways of FOXO3 during the development of GC.We found that mRNA expression level of FOXO3 was remarkably higher in tumor tissue than in normal tissue, and poor prognoses of GC patients were correlated with higher expression of FOXO3. We also found that hsa-miR-18a-5p and hsa-miR-18b-5p can interact with FOXO3 and that high expression of hsa-miR-18a-5p and hsa-miR-18b-5p predicted better prognoses in GC patients. TP53 mutation was significantly associated with high FOXO3 expression, while ARID1A mutation was associated with low FOXO3 expression. Multiple immune cells were found to be related to the expression of FOXO3, and lower expression of FOXO3 may be better suited to immune checkpoint blockade treatment.We find that FOXO3 is a potential oncogene and that the transcript level of FOXO3 is related to the mutation of TP53 and ARID1A. In addition, FOXO3 may influence immune infiltration and different signal pathways through sponge adsorption of miRNA to impact the prognoses of stomach adenocarcinoma patients.