TNFAIP3 and splenic marginal zone lymphoma: These most notably include inactivating mutations in the negative regulator TNFAIP3 (A20), which are detected in ~30% of MALT lymphomas and in 10–15% of splenic and nodal MZLs, and inactivating mutations in the transcription factor KLF2, which have been reported in 20–40% of SMZL and in 17% of NZML (reviewed in References [160,161].