IL-34 is a secreted glycoprotein, synthesized as a 242 amino acid precursor that contains a 20 amino acid signal sequence and a 222 amino acid mature chain. Mature human IL-34 forms a homodimer, consisting of 39 kD monomers. IL-34 is highly conserved among mammals. Human IL-34 has sequence identity of 99.6%, 72% and 71% with chimpanzee, rat, and mouse IL-34, respectively. IL-34 is widely expressed in many tissues, but most abundant in the spleen. IL-1beta and TNF-alpha can induce the expression of IL-34 mRNA in osteoblasts. Also, IL-34 is induced in macrophages infected with equine infectious anemia virus (EIAV). Functionally, IL-34 increases monocyte viability, induces macrophage proliferation, and synergizes with other cytokines to generate macrophages and osteoclasts from cultured progenitors. Although IL-34 has no sequence homology with M-CSF (also CSF-1), it binds to the CSFR, the same receptor for M-CSF. IL-34 and M-CSF show an equivalent ability to support cell growth or survival, but they are not identical in biological activity and signal activation. These cytokines also have differing abilities to induce the production of chemokines (MCP-1 and eotaxin-2) in primary macrophages. IL-34 has been implicated in some disease processes. For example, IL-34 expression is associated with synovitis severity in rheumatoid arthritis (RA) patients. IL-34 elevation in plasma from RA patients was decreased after the administration of disease-modifying anti-rheumatic drugs (DMARDs). Also, strategies of targeting CSF1/CSF1R are already in preclinical and clinical studies for treatment of inflammatory diseases. In addition, it has been shown that IL-34 can enhance the neuroprotective property of microglia and therefore, this may be an effective approach against oAbeta (oligomeric beta-amyloid) neurotoxicity in Alzheimer’s disease. LEGEND MAX(TM) Human IL-34 ELISA Kit is a Sandwich Enzyme-Linked Immunosorbent Assay (ELISA) with a 96-well strip plate that is pre-coated with a capture antibody specific for human IL-34. This kit is specifically designed for the accurate quantitation of human IL-34 from cell culture supernatant, serum, plasma(EDTA) and other biological fluids. It is analytically validated with ready-to-use reagents.