Since most new (8- or 10-color) flow cytometry instruments allow to combine the required antibody into a single tube, ERIC group has developed a core panel of six monoclonal antibodies (CD19, CD20, CD5, CD43, CD79b, CD81), which is applicable to >95% of typical CLL cases and is feasible in most laboratories [84]. This evidence concerns the gene CD5 and B-cell chronic lymphocytic leukemia.