Gastric cancer (GC) is one of the most common malignancies, with an ever-increasing incidence and high mortality rate. Chromobox4 (CBX4), also named hPC2, is a small ubiquitin-related modifier (SUMO) E3 ligase. Previous studies have found that high CBX4 expression is associated with tumor size, pathologic differentiation and decreased patient survival in hepatocellular carcinoma (HCC). However, the expression and prognostic value of CBX4 in GC have not been clarified. In our study, ONCOMINE, UALCAN, Kaplan-Meier Plotter, cBioPortal, DAVID 6.8 and TIMER were utilized. RT-PCR, immunohistochemistry (IHC), Western blot, CCK-8 assay, cell apoptosis assay, cell cycle assay were used to further verify in GC tissue samples or cell line. The transcriptional and protein level of CBX4 in GC tissues was found significantly elevated and a significant association between the expression of CBX4 and clinicopathological parameters was found in GC patients. Low expression of CBX4 in GC patients were correlated with a significantly improved prognosis. The functions of CBX4 are primarily related to the stem cell pluripotency signaling pathway, Hippo signaling pathway, HTLV-I infection, Notch signaling pathway, and N-glycan biosynthesis. Our results may provide novel insights for the selection of therapeutic targets and prognostic biomarkers for GC.

胃癌（GC）是最常见的恶性肿瘤之一，其发病率和死亡率不断增加。Chromobox4 (CBX4)，也称为 hPC2，是一种小的泛素相关修饰剂 (SUMO) E3 连接酶。先前的研究发现，CBX4 的高表达与肝细胞癌 (HCC) 的肿瘤大小、病理分化和患者存活率降低有关。然而，CBX4在GC中的表达和预后价值尚未阐明。在我们的研究中，使用了 ONCOMINE、UALCAN、Kaplan-Meier Plotter、cBioPortal、DAVID 6.8 和 TIMER。RT-PCR、免疫组织化学（IHC）、Western印迹、CCK-8测定、细胞凋亡测定、细胞周期测定用于在GC组织样品或细胞系中进一步验证。发现 GC 组织中 CBX4 的转录和蛋白质水平显着升高，并且在 GC 患者中发现 CBX4 的表达与临床病理参数之间存在显着关联。GC 患者中 CBX4 的低表达与预后的显着改善相关。CBX4 的功能主要与干细胞多能性信号通路、Hippo 信号通路、HTLV-I 感染、Notch 信号通路和 N-聚糖生物合成有关。我们的结果可能为 GC 的治疗靶点和预后生物标志物的选择提供新的见解。CBX4 的功能主要与干细胞多能性信号通路、Hippo 信号通路、HTLV-I 感染、Notch 信号通路和 N-聚糖生物合成有关。我们的结果可能为 GC 的治疗靶点和预后生物标志物的选择提供新的见解。CBX4 的功能主要与干细胞多能性信号通路、Hippo 信号通路、HTLV-I 感染、Notch 信号通路和 N-聚糖生物合成有关。我们的结果可能为 GC 的治疗靶点和预后生物标志物的选择提供新的见解。