Because, to our knowledge, BCL2 rearrangement has not been reported in PCNS DLBCL [35,42], the type of HGBL that will be encountered in PCNSL will most likely be HGBL, NOS, or HGBL with MYC and BCL6 rearrangements. The gene discussed is BCL6; the disease is diffuse large B-cell lymphoma.