High proliferation index in the MYC only-rearranged and BCL6 DHL cases were mostly associated with low or equivocal CD10 expression and co-immunopositivity of MUM1, MYC, BCL2 and BCL6 protein expression, and these patients were more likely to be non-GCB type DLBCL. The gene discussed is IRF4; the disease is diffuse large B-cell lymphoma.