Bayesian colocalization tests between spatial cis-eQTL signals and disease-associated signals were conducted for genomic regions marked by the 7 identical SNPs that were strongly associated (p < 10–8) with both T1D and T2D (i.e. SH2B3, MAPK14, CTRB1/2, INS, ASCL2/MIR4686, and HLA region). This evidence concerns the gene CTRB1 and type 1 diabetes mellitus.