目的·探讨ⅡA组磷脂酶A2（phospholipase A2 group ⅡA，PLA2G2A）在肾乳头状细胞癌（kidney renal papillary cell carcinoma，KIRP）中的表达及临床意义，为寻找KIRP靶向治疗靶点提供新的思路。方法·使用SangerBox在线软件分析PLA2G2A在泛癌中的表达水平及其与泛癌预后、免疫浸润的关系。在此基础上，借助UCSC xena数据库分析PLA2G2A在KIRP中的表达水平，并利用UALCAN数据库和TIMER数据库分别分析PLA2G2A与KIRP患者总生存期和免疫浸润的关系。此外，通过LinkedOmics数据库对KIRP中PLA2G2A进行相关基因分析及基因本体论（Gene Ontology，GO）功能分析和京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes，KEGG）信号通路富集分析。结果·PLA2G2A在包括KIRP在内的15种来自癌症基因组图谱（The Cancer Genome Atlas，TCGA）数据库的肿瘤样本组织中呈显著低表达，结合基因型-组织表达（Genotype-Tissue Expression，GTEx）数据库进一步发现PLA2G2A在KIRP中显著低表达。同时研究结果显示，PLA2G2A的表达水平与多种肿瘤的预后及免疫浸润密切相关；且PLA2G2A在KIRP中的表达水平越高，患者预后越差、免疫浸润丰度越高。GO功能分析结果显示：KIRP中PLA2G2A在生物过程（biological process，BP）方面主要富集于生物调节和代谢等过程，在细胞组分（cell component，CC）方面主要富集于细胞膜和细胞核等，在分子功能（molecular function，MF）方面主要富集于蛋白质结合和离子结合等。KEGG信号通路富集显示：与PLA2G2A正相关的通路主要富集于细胞周期、核糖体、蛋白酶体、系统性红斑狼疮、抗原加工和提呈等信号通路；与PLA2G2A负相关的通路主要富集于柠檬酸循环、丙酮酸代谢、碳代谢等信号通路。结论·PLA2G2A在KIRP中呈显著低表达，但其在KIRP中的表达水平越高，患者预后越差、免疫浸润丰度越高；KIRP中PLA2G2A正相关通路主要富集于细胞周期、免疫相关通路（如系统性红斑狼疮、抗原加工和提呈）等，其负相关通路主要富集于柠檬酸循环、丙酮酸代谢等。因此，PLA2G2A在KIRP的发生发展中到底发挥抑癌还是促癌作用，还需进一步深入探究。

Objective ·To investigate the expression and clinical significance of phospholipase A2 Group ⅡA (PLA2G2A) in kidney renal papillary cell carcinoma (KIRP), and provide new ideas for seeking KIRP targets. Methods ·The expression level of PLA2G2A in pan-cancer and its relationship with prognosis and immune infiltration were analyzed by online software SangerBox. On this basis, the expression level of PLA2G2A in KIRP was analyzed with the help of the UCSC xena database; the correlation between PLA2G2A expression and prognosis and immune infiltration of KIRP were analyzed by using the UALCAN database and the TIMER database, respectively. In addition, the LinkedOmics database was used to analyze the related genes, Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment of PLA2G2A in KIRP. Results ·PLA2G2A was significantly low expressed in 15 tumor samples from The Cancer Genome Atlas (TCGA) including KIRP. It was further validated that PLA2G2A was significantly lower expressed in KIRP with the help of Genotype-Tissue Expression (GTEx) database. The expression level of PLA2G2A was closely related to the prognosis and immune infiltration of various tumors. The higher the expression level of PLA2G2A in KIRP was, the worse the prognosis and the higher the abundance of immune infiltration were. GO analysis showed that PLA2G2A was mainly enriched in biological regulation and metabolic process in biological process (BP), cell membrane and nucleus in cell component (CC), and protein binding and ion binding in molecular function (MF). KEGG pathway enrichment analysis suggested that the pathways positively correlated with PLA2G2A were enriched in ribosome, cell cycle, proteasome, systemic lupus erythematosus and antigen processing and presentation, while the pathways negatively correlated with PLA2G2A were enriched in citrate cycle, pyruvate metabolism, and carbon metabolism. Conclusion ·PLA2G2A is significantly lower expressed in KIRP. Unexpectedly, the higher the expression level of PLA2G2A in KIRP is, the worse the prognosis and the higher the abundance of immune infiltration are. In KIRP, the PLA2G2A positively correlated pathways are mainly enriched in cell cycle and immune-related pathways (such as systemic lupus erythematosus, antigen processing and presentation), while the negatively correlated pathways are mainly concentrated in citric acid cycle and pyruvate metabolism signaling pathways. Thus, it is needed to be further explored whether PLA2G2A plays a role in the development of KIRP as a tumor suppressor or an oncogene.