NKG2D Ligand 4 (NKG2D ligand 4, N2DL-4, NKG2DL4, Lymphocyte effector toxicity activation ligand, RAE-1-like transcript 4, RL-4, Retinoic acid early transcript 1E, RAET1E, ULBP4)

NKG2D ligand 4 (ULBP4) acts as a ligand for the NKG2D receptor on the surface of NK cells. Its binding to the receptor induces expansion of anti-tumor cytotoxic lymphocytes. It is expressed mainly in skin, also in testes or trachea. It is up-regulated in different tumors.NKG2D ligand 4 (ULBP4) does not interacts with the CMV glycoprotein UL16.NKG2D ligand 4 (ULBP4) is expressed in two variants, as a membrane and soluble isoform.