Intracellular adhesion molecule‐3 (ICAM‐3), also known as CD50, is a member of the Ig superfamily of calcium-independent transmembrane glycoproteins. ICAM‐3 is a ligand for the beta2‐integrins, lymphocyte function associated antigen‐1 (LFA‐1/alphaLbeta2) and alphaDbeta2, as well as DC‐specific ICAM‐3 grabbing nonintegrin (DC‐SIGN), a c-type lectin receptor. ICAM‐3 is a cell surface adhesion molecule expressed by resting T cells and antigen presenting cells (APCs). ICAM‐3/LFA‐1 binding mediates adhesion between APCs and T cells and induces co-stimulatory signals important for immune response (e.g., Ca2+mobilization and tyrosine phosphorylation). Binding with DC‐SIGN, expressed by dendritic cells (DC), facilitates DC‐T cell binding, which leads to T cell activation and proliferation. ICAM‐3 plays a dual role in apoptotic cell clearance of leukocytes by promoting chemoattraction of macrophages to sites of cell death and by mediating tethering of apoptotic cells to macrophages for phagocytosis. Soluble ICAM‐3 has been detected in circulation of healthy individuals and elevated levels are observed in the serum of patients with autoimmune diseases such as MS, lupus, and rheumatoid arthritis. PeproTech's CHO‐derived Recombinant Human ICAM‐3 Fc is a glycosylated, disulfide‐linked homodimer of 689 amino‐acid‐residues whose monomer consists of the 456‐amino‐acid extracellular portion of ICAM‐3 fused to the 231‐amino‐acid length Fc portion of human IgG by two glycine residues. The calculated molecular weight of monomeric CHO cell‐derived Recombinant Human ICAM‐3 Fc is 75.5 kDa; however, due to glycosylation, it migrates at an apparent molecular weight of approximately 130‐140 kDa by SDS‐PAGE analysis under reducing conditions.