Crick, Watson, and colleagues revealed the genetic code in 1953, and since that time, remarkable progress has been made in understanding what makes each of us who we are. Identification of single genes important in disease, and the development of a mechanistic understanding of genetic elements that regulate gene function, have cast light on the pathophysiology of many heritable and acquired disorders. In 1990, the human genome project commenced, with the goal of sequencing the entire human genome, and a "first draft" was published with astonishing speed in 2001. The first draft, although an extraordinary achievement, reported essentially an imaginary haploid mix of alleles rather than a true diploid genome. In the years since 2001, technology has further improved, and efforts have been focused on filling in the gaps in the initial genome and starting the huge task of looking at normal variation in the human genome. This work is the beginning of understanding human genetics in the context of the structure of the genome as a complete entity, and as more than simply the sum of a series of genes. We present 3 studies in this review that apply genomic approaches to leukemia and to transplantation to improve and extend therapies.