As of May 30, 2012, the catalog of published genome-wide association studies (GWAS)1 lists an impressive 1269 GWAS, covering a broad spectrum of conditions including Alzheimer disease, breast cancer, and human immunodeficiency virus susceptibility.2 The catalog also contains studies on common traits such as height and freckles, as well as responses to drugs for various medical conditions. It is difficult to discuss GWAS without sounding megalomaniacal. Considerably more than 1000 published GWAS, replication studies, and meta-analyses have been conducted in an unprecedented global research effort in only 7 years. Most GWAS have included hundreds or even thousands of patients and controls, have hundreds of thousands of participants worldwide, and although genotyping costs have plummeted in recent years, hundreds of millions of research dollars have been spent on GWAS since 2005.