淋巴细胞活化蛋白3属于免疫球蛋白超家族，包含4个胞外免疫球蛋白样结构域。lag3基因包含8个外显子。序列数据、外显子/内含子组织和染色体定位均表明LAG3与CD4有密切关系。
Lymphocyte-activation protein 3 belongs to Ig superfamily and contains 4 extracellular Ig-like domains. The LAG3 gene contains 8 exons. The sequence data, exon/intron organization, and chromosomal localization all indicate a close relationship of LAG3 to CD4.