Genetically, GCB and ABC DLBCL present a series of subtype-specific lesions that explain can explain the different biology of the disease, but they also share others that, with a couple of exceptions (BCL6 and MEF2B alterations), are not DLBCL specific and can be observed in other lymphoma types or even in other cancers. Here, MEF2B is linked to aneurysmal bone cyst.