The world of science is one of constant experimentation. But what does that word, experimentation, actually mean? Experimentation is the act or process of trying out a new procedure, idea, or activity. The scientists at the National Institute of Environmental Health Sciences do a lot of "experimenting" to determine how things in our environment affect our bodies. Their experiments help us determine what role environmental exposures and/or our unique genetic structures play with regard to human health. Armed with such knowledge, they may be able to discover some way to prevent that from happening.