<strong>Immunofluorescent Staining:</strong> Human peripheral blood mononuclear cells were labeled with either Mouse anti-Human CD3 (IgG1) (A), anti-Human CD5 (IgG2a) (B), anti-Human CD22 (IgG2b) (C), anti-Human IgD (IgG3) (D) or anti-Human CD57 (IgM) (E). After washing the cells were then stained with Goat anti-Mouse Ig-R-PE Cat.-No AP32278RP (0.1ug/10<sup>6</sup> cells), following which lymphocytes were gated and analyzed by Flow Cytometry.