There were no SNPs within the gene boundaries (±0 kb) for 73 hypothesis-driven candidate genes and no SNPs within expanded gene boundaries (±10 kb) for 27 genes (Table S3). Hypothesis-driven candidate genes with no ISC coverage were excluded from enrichment analyses. Of the ~1.9 million ISC SNPs, 56,981 mapped within hypothesis-driven candidate genes (±0 kb) and 65,803 mapped within expanded gene boundaries (±10 kb).