Recurrent inactivating mutations in Kruppel-like factor 2 (KLF2),have been reported in approximately 40% of splenic marginal zone lymphomas (SMZL) but are rarely present in other B-cell lymphomas, according to one study. The majority of KLF2 mutations were frameshift indels or nonsense changes, with missense mutations clustered in the C-terminal zinc finger domains. Functional assays showed that these mutations inactivated the ability of KLF2 to suppress NF-κB activation. IGHV1-2 rearrangement and 7q deletion were primarily seen in SMZL with KLF2 mutation, while MYD88 and TP53 mutations were nearly exclusively found in those without KLF2 mutation. NOTCH2, TRAF3, TNFAIP3 and CARD11 mutations were observed in SMZL both with and without KLF2 mutation. The prognostic and therapeutic implications, if any, of KLF2 alterations in SMZL has yet to be fully elucidated.