HLA-B and spondyloarthropathy: The HLA-B27 subtypes that are related to spondyloarthritis (SpA), namely B*27:02, B*27:05, and B*27:07, have a higher propensity to aggregate in cytoplasmic vesicles and form intracellular oligomers compared to the non-SpA-associated subtypes HLA-B*07:02 and HLA-B*27:06.