Steve McCarroll, an institute member at the Broad Institute, director of genetics for the Stanley Center for Psychiatric Genetics, and an associate professor at Harvard Medical School, takes us beyond single base-pair deletions and misspellings to explore variations in the human genome on a structural level. With the analytical tools available today to examine huge lengths of DNA, McCarroll and others are linking these structural differences to human health and our risk of developing diseases such as schizophrenia and cancer.