Chronic lymphocytic leukemia diagnosis requires the presence of ≥ 5 x109/l monoclonal B-cells exhibiting characteristic immunophenotype initially described by Estella Matutes” Matutes scores MS” [3] [surface membrane immunoglobulin (SmIg) weak, CD5+, CD19+, CD23+, CD22 weak/-, and FMC7 –], that was modified later by replacing CD22 by CD79b [4]. Here, MS4A1 is linked to B-cell chronic lymphocytic leukemia.