Genomic medicine, sometimes also known as personalized medicine, is a way to customize medical care to your body's unique genetic makeup. Each of the cells in the body contains DNA, the molecules you inherit from your parents that determine how your body looks and functions. DNA is arranged like a twisted ladder, with information stored in the arrangement, or sequence, of the rungs. Sections of the DNA ladder that contain information needed to make proteins are known as genes. The entire structure is the genome. A nearly complete map of the DNA sequence was completed in 2003, and since then, scientists have worked to understand how each gene functions and how it is coordinated with every other gene. The human genome may contain 20 000 to 23 000 genes.