NFKB1 and aneurysmal bone cyst: In B-lymphocytic malignancies, activating mutations of positive regulators or inactivating mutations of negative regulators of NF-κB signaling have been reported, specifically in myeloma, activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL), and mucosa-associated lymphoid tissue (MALT) lymphoma, all of which result in constitutive NF-κB activation [33], [34].