CD58, also known as lymphocyte function-associated antigen 3 (LFA-3) is a 45-70 kD cell surface protein that is a member of the immunoglobulin superfamily. Alternative splicing of CD58 gives rise to transmembrane and glycosylphosphatidylinositol (GPI)-anchored forms on cell surface. CD58 is expressed on both hematopoietic and non-hematopoietic cells including B cells, T cells, monocytes, erythrocytes, endothelial cells, epithelial cells, and fibroblasts. High levels are observed on memory T cells and dendritic cells. CD58 expressed on antigen presenting cells and target cells enhances T cell recognition via the binding of its cognate ligand, CD2, on the T cell surface.