MCL has a distinct immunophenotype, expressing CD5, BCL-2, CD20, IgM/IgD, CD22, and CD79, being negative for CD10 and BCL-6, and overexpressing cyclin D1 [due to t(11; 14) (q13; q32) translocation, a genetic hallmark of MCL] and the transcription factor SOX11 (53–55). The gene discussed is CCND1; the disease is mantle cell lymphoma.