CD48 is a member of the CD2 subfamily of the immunoglobulin superfamily (IgSF) which includes SLAM (signaling lymphocyte activation molecules) proteins, such as CD84, CD150, CD229 and CD244. CD48 is found on the surface of lymphocytes and other immune cells, dendritic cells and endothelial cells, and participates in activation and differentiation pathways in these cells. CD48 was the first B-cell-specific cellular differentiation antigen identified in transformed B lymphoblasts. CD48 interaction with CD2 has been shown to promote lipid raft formation, T cell activation and the formation of caveolae for macrophages through cell signal transduction via GPI moieties.