Sequencing the human genome, which consists of 3,000,000,000 letters (or "bases") in a particular sequence, was a landmark in human history - a giant step forward in our understanding of ourselves as a biological species, and in our ability to use that knowledge to advance the cause of human health. This program addresses biological nanotechnology, how cells operate in our bodies, explaining how these "nanomachines" work. From the Series:Science Forum