link was established when an LD SNP was reported associated with a gene with nominal p-value less than 10−6 in any GTEx tissue [13]. Using a cutoff of 10−12 makes little difference to results (S20 Table). A DHS-based gene-trait link was established when an LD SNP was located in a DNAse I hypersensitivity site correlated with gene expression with one-sided permutation p-value 1.000 (from 1000 replicates) [28]. All linked genes were mapped to Ensembl IDs, and links to genes not annotated as protein coding by Ensembl were removed from the dataset. Additional details are available in S3 Text.
