Comparison of immunogenetic features between CBL-MZ and primary splenic small B-cell lymphomas. (A) IGHV gene repertoire. The IGHV gene repertoire of CBL-MZ is significantly different from SMZL and resembles SDRL.42 (B) Somatic hypermutation. Most CBL-MZ cases carry a significant mutational load as evidenced by the germline identity of the clonotypic IG genes. Comparisons with SMZL and SDRL.42