Main discerning features of the BL genomic subgroups: rearrangements between MYC and IG genes are universal, but the SHM breakpoints are more common in DGG-BL, which is strongly associated with EBV infections; DGG-BL and IC-BL acquire separate sets of additional mutations that act in concert with the MYC-induced cell growth and proliferation program; TP53 mutations occur frequently in all subtypes, but a small subset (termed Q53-BL) lacks any additional driver mutations. IG, immunoglobulin; SHM, somatic hypermutation; EBV, Epstein-Barr virus.