First, we identify a 5 kb region in intron 2 of STARD10 that: (1) captures the T2D GWAS association signal; (2) is associated with STARD10, but not ARAP1, mRNA expression in human islets and physically interacts with the promoter for the STARD10 isoform dominant in islets; (3) overlays a stretch-enhancer in islets; (4) is correlated with local chromatin structure in islets; and (5) contains allelic variants shown experimentally to alter enhancer function. This evidence concerns the gene STARD10 and type 2 diabetes mellitus.