CD58 is a glycoprotein of 65-70 kDa, either transmembrane or glycosylphosphatidylinositol (GPI)-anchored. CD58 was first described as the lymphocyte-function associated antigen 3 (LFA-3). LFA-3 was further shown to interact with CD2 suggesting an important role in various immunological responses via T-cell adhesion and activation. CD58 mediates adhesion between killer and target cells, antigen presenting cells and T cells. This antigen is widely expressed on leucocytes, erythrocytes and endothelial cells.