HLA-C and rheumatoid arthritis: In addition to SLE risk coming from identical positions across MHC subunits, other diseases with residue-mapped risk similarly co-localize, e.g. DRB1-67 in Type 1 diabetes (T1D)[14] and Sjögren’s syndrome[31] with A-152/C-152/DRB1-67 from this study; B-70 and 97 in psoriasis[14] with A-70 and A-97/DRB1-9 from this study; and DRB1-11, B-9, and DPB1-9 in RA[29] with DRB1-11, B-9/C-9, and DRB1-9/A-97 from this study, respectively.