For all diseases except RA and T1D the distribution changes only marginally after removal of the MHC region (Additional File 1: Figures S1 to S7); but for RA-MHC and T1D-MHC enrichment in the vicinity of genes is substantially reduced (Figure 2, Additional File 1: Figures S2 and S3). This evidence concerns the gene HLA-C and rheumatoid arthritis.