In this context, similar to systemic ABC or non-GCB DLBCL and other subtypes of B-cell lymphomas, a substantial number of CNS DLBCL harbor chromosome 6q deletions (up to 71% in prior studies and 38% in our study), which can result in the loss of at least two tumor suppressor genes (PRDM1 and TNFAIP3) that have been shown to deregulate NF-κB activity [14], [24]–[26]. The gene discussed is PRDM1; the disease is aneurysmal bone cyst.