fig4

Figure 4. Putative SMZL disease subtypes. Collectively, data from different studies support a distinct sub-group of SMZL (Group 1) driven by: IGHV1-02 usage, DNA hypo-methylation and over expression of genes involved in B-cell activation, NF-κB, and those encoding for the polycomb repressor region, and recurrent genomic lesions (deletion of 7q and somatic mutations in KLF2 and NOTCH2). Sub-groups 2-4 are less well supported due to a limited number of cases and lack of functional evidence. Further work is necessary to delineate and characterise them fully. SMZL: Splenic marginal zone lymphoma; IGHV: immunoglobulin heavy chain variable region; CNAs: copy number alterations; MZ: marginal zone; TLR: toll-like receptor; BCR: B-cell receptor.