CD85 antigen-like family member J (CD85J) is also known as Leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1 or LIR-1), Immunoglobulin-like transcript 2 (ILT-2), Monocyte/macrophage immunoglobulin-like receptor 7 (MIR7), which belongs to leukocyte immunoglobulin-like receptor (LIR) family. CD85J / LILRB1 Contains 4 Ig-like C2-type (immunoglobulin-like) domains. CD85J / LIR-1 is expressed predominantly on B-cells and monocytes. CD85J is receptor for class I MHC antigens and recognizes a broad spectrum of HLA-A, HLA-B, HLA-C and HLA-G alleles and is also receptor for H301/UL18, a human cytomegalovirus class I MHC homolog. Ligand binding results in inhibitory signals and down-regulation of the immune response. CD85J / LILRB1 interaction with HLA-B or HLA-E leads to inhibition of the signal triggered by FCER1A and inhibits serotonin release. CD85J / LILRB1 inhibits FCGR1A-mediated phosphorylation of cellular proteins and mobilization of intracellular calcium ions.