In 1995, a public health service workshop in the United States put forward recommendations for case definitions and medical follow-up.2 Subsequently, over the next ten years, an increasing number of studies on different populations around the world, using different flow cytometry approaches, recognized that CD5+ and CD5− monoclonal B-lymphocytes could be found in individuals with no clinically apparent hematological disease.3 This evidence concerns the gene CD5 and hematologic disorder.