The answer may be found in the sprawling network of proteins produced by human cells at the direction of the genes. Some researchers are now theorizing that the human genome, the term for the complete set of genes, may provide cells with instructions to make as many as 300,000 different proteins. Over the last few years, scientists at major pharmaceutical companies and a slew of smaller biotech firms have turned their attention to such proteins, racing one another to discover new ones and determine how they work. That's because proteins likely hold the ultimate key to new disease-diagnostic tests and novel drugs. There is a host of interactions, and it's the interactions that make a cell healthy or unhealthy.
Cells produce proteins by reading information inside genes.
So discovering genes provides scientists with critical clues about proteins. Proteins, in turn, act as the building blocks of life, the chemical messengers between cells and other proteins, and the freight carriers that transport other proteins around the body, often via the bloodstream. By understanding proteins, scientists believe they can finally solve the basic biochemical mechanisms underlying sickness and health. While we have the sequence of the entire genome, we don't know the identity of all the genes and the proteins they encode. Besides satisfying the scientific community, detailed knowledge about proteins has become critical for protecting biological discoveries for commercial gain.