NFKB1 and primary central nervous system lymphoma: Interestingly, four independent studies [42,43,44,45] that analyzed large series of de novo DLBCL irrespective of their site of manifestation identified a genetic subgroup termed MCD, C5, or MYD88 that perfectly matched the characteristics of PCNSL, with MYD88 and CD79B mutations; BCR-dependent NF-κB activation; an ABC profile; CDKN2A, ETV6, BTG1/2, and TBL1XR1 genetic alterations; and a high expression of MYC-induced genes.