CD102, also known as intercellular adhesion molecule 2 (ICAM-2), is a type I transmembrane glycoprotein belonging to the immunoglobulin superfamily. It is widely expressed on resting lymphocytes, monocytes, platelets, and vascular endothelial cells. CD102 plays a crucial role in immune response by binding to leukocyte integrins such as LFA-1 (CD11a/CD18) and mediating adhesive interactions important for lymphocyte recirculation, antigen-specific immune responses, and natural killer cell-mediated clearance. Additionally, it has been identified as a biomarker for long-lived plasma cells in non-human primates and is involved in maintaining the longevity of these cells in the bone marrow. Elevated levels of CD102 have also been associated with conditions like hemorrhagic fever with renal syndrome and idiopathic pulmonary fibrosis.