TNFAIP3 and aneurysmal bone cyst: In more than half of ABC DLBCL cases, deletions or inactivating mutations in the TNFAIP3 (A20) tumor suppressor gene and genetic defects in some other protooncogenes and tumor suppressor genes that regulate the NF-κB signaling pathway were found to have activated this signaling pathway irregularly (Compagno et al., 2009).