The clone UCHL1 recognizes 180-185 KD surface antigen known as CD45RO commonly expressed by thymocytes, a subset of resting, memory and activated T cells, activated monocytes/macrophages, granulocytes and myeloma cells. CD45RO is the shortest isoform of a receptor-type protein tyrosine phosphatase, CD45 glycoprotein. It plays important rule in development of lymphocytes and antigen signaling, promotes cell survival by modulating integrin-mediated signal transduction pathway and is also involved in DNA fragmentation during apoptosis.