Factors that predict DLBCL prognosis include COO4 and MYC translocation status.6, 8 For COO, the poorer prognosis of ABC-DLBCL is frequently associated with constitutive activity of the NF-κB pathway and mutations in upstream activators such as MYD88,19CARD11(ref. 13) and CD79B.12 However, there is conflicting data regarding its usefulness as a predictive biomarker for DLBCL clinical failure.23c-MYC rearrangements or MYC ‘double hits' detected by fluorescence in situ hybridization are correlated with poor prognosis, but they occur in only 6–14%(refs 6, 24) of DLBCL cases. This evidence concerns the gene NFKB1 and diffuse large B-cell lymphoma.