The incidence of aCLL is reported to be 7% among all B-LPDs diagnosed by flow cytometry.13 Atypical CLL is described as having a lower Matutes score owing to the unusually brighter expression of sIg or CD79b, lack of CD5 or CD23, or positivity for FMC7/CD20.11,13,14 These immunophenotypic changes may, however, be secondary to trisomy 12, acting as a confounding variable.11,14. The gene discussed is MS4A1; the disease is B-cell chronic lymphocytic leukemia.