GWAS: “G-whiz!” or “GWAShed-up”? Genome-wide association studies (GWASs) link single-nucleotide variations in the human genome to a complex trait. Over the past 4 years, these ground-breaking studies have identified almost 1000 alleles increasing an individual's risk for developing common diseases, such as cancer and obesity. However, these variants often explain only a small portion of the heritability of most complex traits. This Genomics Select highlights recent studies suggesting two specific strategies for finding this “missing heritability”: increasing the statistical power of GWASs and characterizing rare structural variations in the human genome not traditionally explored by GWASs.