Genome-wide association study (GWAS) signals replicated in an electronic medical record (EMR) study at somewhat lower ORs. For each disease, the odds of identifying a particular single nucleotide polymorphism (SNP) involved (column 2) in a carefully controlled GWAS study (red squares) was compared to the researchers' ability to identify it in their EMR study (red diamonds). And although the blue diamonds are a bit to the left of the red squares, most of the blues (except perhaps the three at the bottom) are above the 1.0 OR. AF, atrial fibrillation; CD, Crohn's disease; MS, multiple sclerosis; RA, rheumatoid arthritis; T2D, type 2 diabetes. Reprinted from Ritchie et al with permission from Elsevier.