CD48 (Cluster of Differentiation 48) is a universal cell membrane protein present on all leukocytes: lymphocytes and other immune cells, dendritic cells and endothelial cells, and participates in activation and differentiation pathways in these cells. CD48 interacts with CD2 and is involved in T-cell activation. This antibody reacts with 45 kDa glycosylphosphatidylinositol linked cell surface molecules.