Charting the map of life.

Scientists expect that mapping the human genome will lead to a host of innovations in biology and research. For example, it may become possible to use DNA microarrays to accurately diagnose cancer and infectious disease subtypes and to predict clinical outcomes. Scientists might also use the genome to look at the interactions of the environment, genetic makeup, and toxic exposures, including the ability of certain beneficial genes to detoxify the body and resist disease. But despite the great potential of the field of genomics, scientists caution that public expectations need to be tempered by reality. People are as much a product of their environment as they are of their genes, say experts, and to suggest that genetics is the sole determinant that defines humans as individuals stretches the science beyond the current data.