Leukocyte Immunoglobulin-like Receptor Subfamily A Member 5（LILRA5）is a member of the leukocyte immunoglobulin-like receptors (LILR), comprise a family of activating and inhibitory type immunoreceptors. LILRA5 consists of a 227 amino acid (aa) extracellular domain (ECD), a 21 aa transmembrane segment, and a 10 aa cytoplasmic tail. The ECD contains two Ig-like domains and the transmembrane segment contains a positively charged aspartic acid residue which may mediate its association with the signaling molecule, FcR common gamma chain. LILRA5 is expressed by monocytes, macrophages, and neutrophils. Cross-linking of LILRA5 on monocytes induces the expression of pro-inflammatory cytokines (IL-1beta, IL-6, TNF-alpha) as well as the anti-inflammatory IL-10. It can be detected in tissues of the hematopoietic system, including bone marrow, spleen, lymph node and peripheral leukocytes. Crosslink of ILT-11 on the surface of monocytes has been shown to induce calcium flux and secretion of several proinflammatory cytokines, which suggests the roles of this protein in triggering innate immune responses.