白细胞介素19（IL-19）是单核细胞产生的细胞因子，属于IL-10家族。IL-19蛋白刺激纤维连接蛋白（FN）的表达和组装、转移和乳腺癌（BC）细胞的细胞分裂。IL-19与乳腺发病机制有关，在BC细胞中具有自分泌作用，是许多肿瘤形式（包括乳腺癌）的预后关键指标。增强的IL-19表达与乳腺癌患者的较差临床预后相关，直接增强增殖和迁移，同时也作为肿瘤形成的微环境。我们研究的主要目的是检验IL-19在BC发病机制中的表达谱、功能角色和预后意义，并找出其在BC中的分子机制。在这项工作中，我们使用了各种计算方法和工具，评估了IL-19在BC中的表达谱和预后意义，并发现了IL-19在BC发病机制中的作用。与其他白细胞介素相比，IL-19在BC中高度上调。此外，在激素受体阳性乳腺癌患者中，IL-19的水平高度过表达，主要集中在21-40岁的第三期患者群中。在乳腺癌中，IL-19水平增加，高表达的IL-19与更糟的整体生存率（OS）相关。KEGG分析和基因本体论显示，IL-19在细胞因子活性和受体配体活性以及JAK-STAT信号通路中显著增强。此外，IL-19与IL20RA高度相关，后者与JAK-STAT信号通路相关。体内和体外研究也反映了IL-19的上调增强了肿瘤发展，并通过包括JAK TAT信号通路在内的多条路径影响BC患者的临床预后。总体而言，我们的研究表明，IL-19增加了肿瘤生长，并且通过抑制其功能，结合标准治疗方法，将大大改善BC患者的治疗反应。© 2023年作者。

Interleukin 19 (IL-19) is a cytokine produced by monocytes and belongs to the family of IL-10. The IL-19 protein stimulates fibronectin (FN) expression and assembly, metastasis, and cell division in breast cancer (BC) cells. IL-19, which is connected to breast pathogenesis and has an autocrine action in BC cells, is a key predictor of prognosis for many tumour forms, including breast cancer. Augmented IL-19 expression has been related to poorer clinical outcomes for patients with BC and directly enhances proliferation and migration while also serving as a microenvironment for tumour formation. The main aim of our study was to examine the expression profile, functional role, and prognostic significance of interleukin-19 in BC pathogenesis and also to find out the molecular mechanism of IL-19 in BC. In this work, we used the various computational approach and tools, to evaluate the expression profile and prognostic implication of IL-19 in BC and discover the role of IL-19 in BC pathogenesis. IL-19 was shown to be highly upregulated in BC as compared to other interleukins. Also, its levels were highly overexpressed in liminal BC patients, mostly in 3rd stage groups under the age group of 21-40 years. IL-19 levels were increased in BC and elevated expression of IL-19 was examined to have worse overall survival (OS). The KEGG analysis and gene ontology of IL-19 depict that IL-19 is significantly augmented in cytokine activity and receptor-ligand activity and also in the JAK-STAT signaling pathway. Moreover, IL-19 showed a high correlation with IL20RA, as later is involved with the JAK-STAT signaling pathway. The in-vivo and in-vitro studies have also reflected that upregulation of IL-19 enhances tumor development and affects clinical outcomes in BC patients through several pathways including the JAK TAT signalling pathway. Overall, our study indicates that IL-19 increases tumour growth and that inhibiting it in addition to standard treatments will greatly improve BC patient's therapeutic responses.© 2023 The Author(s).