TNFAIP3 and neoplasm: Later on, two other important achievements came from the same Cologne group through HRS cell microdissection: Kanzler et al. were able to show somatic mutations in the VH gene amplified from HRS cells together with nonfunctional immunoglobulin (Ig) genes [3], and Schmitz et al. identified frequent somatic mutations in the TNFAIP3 (A20) gene in HRS cells, thus establishing these genes as tumor suppressors in the pathogenesis of HL [4].