淋巴细胞活化基因 3（lymphocyte⁃activation gene 3，LAG⁃3）又称 CD223，是一种在活化的 T 细 胞上被发现的跨膜蛋白，其可在活化的 CD4+T、CD8+T 细胞以及 Treg、NK 细胞、B 细胞和 DC 上表达，由胞外 区、穿膜区和胞内区 3 个部分组成。纤维介素蛋白 1（fibrinogen like protein 1，FGL⁃1）作为 LAG⁃3 的一种新 被发现的配体，在体外和体内以受体⁃配体相互依赖的方式对 T 细胞功能发挥抑制作用。本文就 FGL⁃1⁃ LAG⁃3 通路在肿瘤免疫中的作用进行综述，旨在通过揭示 LAG⁃3⁃FGL⁃1 通路在肿瘤免疫中的作用为肿瘤

Lymphocyte ⁃activation gene 3（LAG ⁃3），also known as CD223，is a transmembrane protein found on activated T cells. It can be found on the activated CD4 + T and CD8 +T，as well as on Treg，NK cells，B cells and DC. LAG ⁃3 consists of three parts：the extracellular region，penetrating region and intracellular region. Fibrinogen like protein 1，FGL⁃1，as a newly discovered ligand of LAG⁃3，which can inhibit T cell function in a receptor⁃ligand interdependent manner in vitro and in vivo. We review the role of FGL⁃1⁃LAG⁃3 pathway in tumor immunity，and aim to reveal the role of LAG⁃3⁃FGL⁃1 pathway in tumor immunity and to provide new ideas for tumor immunotherapy.