Biologically activated NF-kB- and JAK2-pathways, for example, by gain of 9p24 are a hallmark of PMBCL together with frequent loss of functional HLA-II complexes.2 It has been described that these differences in biology compared with classic, not otherwise specified diffuse large B-cell lymphoma (DLBCL NOS) is also accompanied by a different, more favorable prognosis with less common late relapses. This evidence concerns the gene JAK2 and diffuse large B-cell lymphoma.