NFKBIE and mantle cell lymphoma: The NF-κB inhibitor I-kappa-B-epsilon (NFKBIE) gene, which encodes IκBε, is targeted by a recurrent 4-bp truncating mutation in addition to rare point mutations in 5–10% of chronic lymphocytic leukemia (CLL)2,3,14–16 and various B-cell lymphomas (BCLs), including diffuse large B-cell lymphoma (DLBCL; 5%), mantle cell lymphoma (5%), splenic marginal zone lymphoma (1.8%), and primary mediastinal B-cell lymphoma (PMBCL; 23% of patients)12,17.