HLA-B and ankylosing spondylitis: The Zernike descriptor approach hasalso been applied to describethe binding groove features of the major histocompatibility complex(MHC) of class I. In this context, we focused on human leukocyte antigenB*27 (HLA-B*27), which is involved in ankylosing spondylitis (AS),an inflammatory rheumatic disease affecting the axial skeleton.35,36 In particular, the subtype HLA-B*2705 is the ancestral allele, whichhas been found to be associated with AS in almost all investigatedpopulations.