IRF4 and diffuse large B-cell lymphoma: For the resulting subnetwork of ABC patients, the hallmark of ABC-DLBCL, as constitutive activation of nuclear factor kappa-B (NFKB) signalling, was confirmed by the enrichment of NFKB pathway (cluster in purple) and up-regulation of well defined ABC genes including IRF4, FOXP1, IL6, BATF and PIM2 among others [30].