Naturally, as one compares the structural variability of different ig domains to their sequence variability, one has to keep in mind the flexibility of a molecule of given sequence, as well as certain additional interactions which might influence the x-ray structure of a molecule - ligand interaction, crystal packing - or plain poorly defined structure (3.0 and 3.2Å resolution), CDR3 listed as poorly defined in the header of file 2gfb - largest cavity in Nicolas Boudins analysis.