However, BL is characterized by intermediate-sized lymphoid cells with almost 100% Ki67 index, positive expression with CD10 and BCL-6, and lack of expression of BCL-2, although the same immuophenotype can be encountered in DLBCL and differentiation is sometimes difficult to make in the absence of molecular/genetic analysis. The gene discussed is BCL6; the disease is diffuse large B-cell lymphoma.