CTLA4（cytotoxic T-lymphocyte associated protein 4），癌症关联基因，基因ID：1493，该基因是免疫球蛋白超家族的成员，编码一种将抑制信号传递给T细胞的蛋白质。该蛋白包含一个V结构域、一个跨膜结构域和一个胞质尾。编码不同亚型的替代转录剪接变异体已经被描述。膜结合异构体作为一个由二硫键连接的同二聚体发挥作用，而可溶性异构体作为一个单体发挥作用。该基因突变与胰岛素依赖性糖尿病、格雷夫斯病、桥本甲状腺炎、腹腔疾病、系统性红斑狼疮、甲状腺相关眼眶病变和其他自身免疫性疾病有关。This gene is a member of the immunoglobulin superfamily and encodes a protein which transmits an inhibitory signal to T cells. The protein contains a V domain， a transmembrane domain， and a cytoplasmic tail. Alternate transcriptional splice variants， encoding different isoforms， have been characterized. The membrane-bound isoform functions as a homodimer interconnected by a disulfide bond， while the soluble isoform functions as a monomer. Mutations in this gene have been associated with insulin-dependent diabetes mellitus， Graves disease， Hashimoto thyroiditis， celiac disease， systemic lupus erythematosus， thyroid-associated orbitopathy， and other autoimmune diseases.关联癌症：非小细胞肺癌。关。