ICOSLG

Chr 21AR

inducible T cell costimulator ligand

Also known as: B7-H2, B7H2, B7RP-1, B7RP1, B7h, CD275, GL50, ICOS-L

NCBI Gene: 23308 ENSG00000160223 UniProt: O75144 OMIM: 605717

ICOSLG encodes a ligand for the T-cell surface receptor ICOS that provides costimulatory signals for T-cell proliferation and cytokine secretion, induces B-cell proliferation and differentiation into plasma cells, and is required for proper neutrophil transmigration in endothelial cells. Mutations cause autosomal recessive immunodeficiency 119, affecting the immune system. The gene shows low constraint to loss-of-function variants (pLI 0.0004, LOEUF 0.92), consistent with recessive inheritance where heterozygous carriers are typically unaffected.

OMIM ResearchSummary from RefSeq, OMIM, UniProt

Enables identical protein binding activity and receptor ligand activity. Involved in T follicular helper cell differentiation. Located in extracellular exosome. Is active in plasma membrane. Implicated in immunodeficiency 119. [provided by Alliance of Genome Resources, Jun 2026]

OMIM ResearchGenerating clinical summary…