Lymphocyte Activation Gene 3 (LAG3)

Lymphocyte-activation protein 3 belongs to immunoglobulin (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.Triebel et al. (1990) identified a novel human gene of the Ig superfamily, which they designated LAG3. Expression of this gene was undetectable in resting peripheral blood lymphocytes, whereas it was found in activated T and NK cells. The corresponding cDNA encodes a 498-amino acid membrane protein with 4 extracellular Ig-like domains. The sequence data, exon/intron organization, and chromosomal localization all indicate a close relationship of LAG3 to CD4. The 2 genes are probably derived from a common evolutionary ancestor.