Amino acid sequence in the V_H3-21–using cases. Of 31 cases, 30 are shown, since the V_H3-21 gene rearrangement in case 31 was nonfunctional with a stop codon in the CDR3. Sequence homology is shown to the germline V_H3-21 gene. Homology to the Ala-Arg-Asp-Ala-Asn-Gly-Met-Asp-Val (ARDANGMDV) CDR3 sequence is also shown. Dots indicate homology with the consensus sequence. A dash indicates that an amino acid is missing compared to the germline sequence. Case 17 displayed an extra amino acid insertion that could not be found in the germline sequence or the remaining sequences.