LILRB1, also known as CD85j and ILT2, is a 110 kDa transmembrane glycoprotein in the LILR immunoregulatory protein family. Mature human LILRB1 consists of a 438 amino acid (aa) extracellular domain (ECD) with 4 tandem Ig-like domains, a 21 aa transmembrane segment, and a 168 aa cytoplasmic domain with 4 inhibitory ITIM motifs.LILRB1 is a receptor for class I MHC antigens. Recognizes a broad spectrum of HLA-A, HLA-B, HLA-C, HLA-G and HLA-F alleles. Receptor for H301/UL18, a human cytomegalovirus class I MHC homolog. Ligand binding results in inhibitory signals and down-regulation of the immune response.

> 95% as determined by Tris-Bis PAGE; > 95% as determined by HPLC