Biotechnology allows the transfer of new genes into animals and humans, the culturing of plants from single cells, and the development of new drugs and diagnostic tests. Knowledge gleaned from the human genome and wedded with biotechnology techniques will play a more and more important role in drug development, gene-therapy treatments, and clinical immunology. For example, the Food and Drug Administration has approved nine genetically engineered monoclonal antibodies for treating several diseases, including cancer. Biotechnology will develop human antibodies and other proteins that can be harvested for therapeutic uses. Clinical diagnostics will remain a mainstay of biopharmaceuticals as companies began uniting genomics with microarray (gene-chip) technology to develop new diagnostic tests and ones that can assess an individual’s risk of developing a genetic disease.

DNA microarrays will prove an even more essential element in drug development than it currently is as researchers exploit the sequencing of the human genome. These arrays contain thousands of separate DNA sequences on a plate roughly the size of a business card. They enable the analysis of a sample of DNA to determine if it contains polymorphisms or mutations. DNA microassays, which are usually prepared by robotic devices, can be used to diagnose various diseases, identify potential therapeutic targets, and predict toxic effects, and one day they will allow customizing drug regimens for individual patients.

Computer modeling and combinatoral chemistry, which enable the rapid creation of thousands of chemical entities and their testing for potential biological activity, hold the promise of new and safer drugs and, perhaps, lower development costs. Companies are devising and using computer models that assess a compound’s absorption, distribution, metabolism, excretion, and toxicity characteristics. The aim is to greatly reduce the number of drugs that go to animal testing and clinical trials, only to prove unacceptable as human therapeutics. Tapping the mapped human genome will reveal many new targets that, combined with computer modeling, will allow drug firms to more rationally design specific drugs, test them at less cost, and feel more confident about them when the companies take them to human trial.

Another area of considerable challenge lies in finding ways to control the interactions of hormones and their receptors and other protein-protein relationships. These interactions present potential drug targets, but devising methods to