NFKB2 and diffuse large B-cell lymphoma: There are very rarely mutations in the genes encoding the five constituent NF-κB proteins [REL, RELA, NFKB1, NFKB2 and RELB are mutated in 0.7%, 0%, 0.7%, 2.2% and 1.5% of DLBCL cases respectively (5)].