Whilst the ultimate goal should be to classify all DLBCLs according to their molecular lesions in order to personalize DLBCL treatment, currently the COO classification is still useful; for example, only 50% of cases fall into the classification scheme by Schmitz and colleagues [53], with the remaining cases being attributed to ABC-, GCB- or unclassified DLBCL subtypes. The gene discussed is ABCB6; the disease is diffuse large B-cell lymphoma.