肺癌是全球恶性癌症中死亡率最高的一种，因此在减少患者死亡方面具有重大全球挑战。在肿瘤学领域，靶向免疫疗法已成为肺癌的一种新型治疗方法。本研究旨在通过铁死亡指数（FPI）和单细胞RNA测序（scRNA-seq）数据分析，探讨肺腺癌（LUAD）免疫治疗的潜在靶点。本研究的发现可以为改进LUAD免疫治疗策略和临床决策提供有价值的见解。 首先，通过FPI对LUAD患者的存活和铁死亡之间的关系进行分析。随后，通过免疫浸润分析和相关统计分析探索铁死亡与免疫细胞的浸润和调节之间的关联。最后，通过GSEA和GSVA分析LUAD患者的主要浸润免疫细胞群体与相关通路和预后之间的关系。为了筛选出调节免疫细胞群体浸润的核心基因，下载了LUAD患者的癌组织和癌旁组织的scRNA-seq数据，并进行了细胞聚类分析、核心亚群细胞鉴定、伪时间分析、单细胞GSVA分析和通路富集分析，识别和功能分析核心调控基因。此外，通过免疫组化检测LUAD组织芯片中的核心功能基因的表达水平，验证其与LUAD患者预后的关系。最后，使用含有WDFY4的慢病毒转化LUAD A549细胞。使用CCK-8、流式细胞术检测细胞凋亡、划痕伤口愈合实验、Transwell迁移实验、异种移植裸鼠模型、免疫组织化学分析等实验方法，探索WDFY4对LUAD的体外和体内生物学效应。 FPI值的存活分析表明，FPI值较小与总体存活时间较长呈正相关。免疫浸润分析及其与FPI值的相关性揭示，B细胞与铁死亡最为密切相关。癌细胞的铁死亡可以促进B细胞群体的浸润和激活，而具有更多B细胞群体浸润的LUAD患者具有更长的长期生存。scRNA-seq数据分析表明，B细胞群体是LUAD中浸润免疫细胞的主要细胞群体之一。在LUAD的B细胞分化的后期阶段，ACAP1、LINC00926、TLR10、MS4A1、WDFY4和TRIM22基因的表达水平下降，而TMEM59、TP53INP1和METTL7A基因的表达水平升高。蛋白质相互作用（PPI）网络分析表明，WDFY4在调控LUAD的B细胞分化中起着重要作用。LUAD组织芯片的免疫组化分析显示WDFY4表达显著降低，与LUAD发生部位密切相关。此外，WDFY4表达较低的LUAD患者预后较差。此外，实验结果表明WDFY4的过表达可以抑制A549细胞的增殖和转移，促进细胞凋亡。还证实WDFY4可以抑制体内癌症生长。 研究结果表明，促进B细胞群体的浸润和激活可以改善LUAD患者的长期生存，从而为LUAD提供了潜在的新型免疫治疗方法。此外，促进癌细胞的铁死亡和上调WDFY4表达已被证明能诱导B细胞群体的浸润和激活。此外，WDFY4的过表达可以显著抑制LUAD的体内和体外生长，突显其作为LUAD免疫治疗靶点的潜力。

Lung cancer exhibits the world's highest mortality rate among malignant cancers worldwide, thereby presenting a significant global challenge in terms of reducing patient mortality. In the field of oncology, targeted immunotherapy has emerged as a novel therapeutic approach for lung cancer. This study aims to explore potential targets for immunotherapy in lung adenocarcinoma (LUAD) through the analysis of Ferroptosis Index (FPI) and Single Cell RNA-Sequencing (scRNA-seq) data. The findings of this research can potentially offer valuable insights for improving LUAD immunotherapy strategies and informing clinical decision-making.Firstly, the relationship between survival and ferroptosis in LUAD patients was analyzed by FPI. Subsequently, the association between ferroptosis and infiltration and regulation of immune cells was explored by immune infiltration analysis and correlation statistics. Lastly, the relationship between major infiltrating immune cell populations and related pathways and prognosis of LUAD patients was analyzed by GSEA and GSVA. To screen out core genes regulating infiltration of immune cell populations, scRNA-seq data of cancer and para-cancerous tissues of LUAD patients were downloaded, followed by cell clustering analysis, cell identification of core subpopulations, pseudotime analysis, single-cell GSVA and pathway enrichment analysis, and identification and functional analysis of core regulatory genes. Moreover, the expression levels of core functional genes in LUAD tissue microarray were detected by immunohistochemistry, and its relationship with the prognosis of LUAD patients was verified. Finally, we used lentivirus with WDFY4 to transfect LUAD A549 cells. CCK-8, flow cytometry apoptosis detection, Scratch wound healing assay, Transwell migration assay, Xenograft nude mice model, immunohistochemical analysis and other experimental methods were used to explore the biological effects of WDFY4 on LUAD in vitro and in vivo.Survival analysis of FPI values in LUAD patients revealed a positive correlation between smaller FPI values and longer overall survival. Immuno-infiltration analysis and its correlation with FPI values revealed that B cells were most strongly associated with ferroptosis. Ferroptosis of cancer cells could promote infiltration and activation of B cell populations, and LUAD patients with more infiltration of B cell populations had longer long-term survival. scRNA-seq data analysis indicated that the B cell population is one of the major cell populations infiltrated by immune cells in LUAD. During the later phases of B cell differentiation in LUAD, there was a decrease in the expression levels of ACAP1, LINC00926, TLR10, MS4A1, WDFY4, and TRIM22 genes, whereas the expression levels of TMEM59, TP53INP1, and METTL7A genes were elevated. The protein-protein interaction (PPI) network analysis indicated that WDFY4 plays a crucial role in regulating B cell differentiation in LUAD. Immunohistochemical analysis of LUAD tissue microarray revealed a significant downregulation of WDFY4 expression, which was closely related to the occurrence sites of LUAD. Moreover, LUAD patients with a low WDFY4 expression exhibited a poorer prognosis. Additionally, experimental findings demonstrated that the overexpression of WDFY4 could inhibit the proliferation and metastasis of A549 cells while promoting apoptosis. It was also confirmed that WDFY4 could inhibit cancer growth in vivo.The results indicate that promoting infiltration and activation of B cell populations could improve the long-term survival of LUAD patients, thereby offering a potential novel immunotherapeutic approach for LUAD. Besides, the promotion of cancer cell ferroptosis and upregulation of WDFY4 expression have been shown to induce the infiltration and activation of B cell populations. Furthermore, the overexpression of WDFY4 can significantly inhibit the growth of lung adenocarcinoma in vitro and in vivo, highlighting its potential as a target for immunotherapy in LUAD.