Centroblastic DLBCL occurs in the setting of mild immunosuppression, has a low frequency of EBV positivity (30–40%) without expression of LMP-1, shows a germinal centre B-cell phenotype (expression of CD10 and BCL6, and lack of expression of CD138 and MUM1), and frequently shows rearrangements of the BCL6 gene. This evidence concerns the gene BCL6 and diffuse large B-cell lymphoma.