A previous study in IBD [27] addressed this question of electrostatic potentials in a slightly different way, motivated by their finding that classical HLA alleles (specifically HLA-DRB1*01:03) better explained the IBD association than did models based on amino acid substitutions, leading the investigators to focus their subsequent efforts on an HLA-DRB1 centric model. Here, HLA-DRB1 is linked to inflammatory bowel disease.