CTRB2 and type 1 diabetes mellitus: For the BCAR1/CTRB1/CTRB2 region, the scores were negatively correlated (r = − 0.20), consistent with studies showing that the G allele of the rs720877 SNP in this region is associated with increased risk of type 1 diabetes but with decreased risk of type 2 diabetes [14, 15, 26].