Biologists traditionally study organisms one gene or one protein at a time. But because organisms are collections of interwoven systems that involve interactions of many molecules, more and more researchers believe a systems-level approach to biology is critical for understanding diseases and developing cures. Gavin MacBeath is working on technology to facilitate that approach. An assistant professor in Harvard University’s chemistry and chemical biology department, MacBeath has found a way to attach thousands of functional protein samples to small glass chips. Using these chips, he can study more than 25,000 interactions between pairs of proteins in a single afternoon. He also plans to look for small molecules that can selectively disrupt interactions- both to learn more about basic biology and to identify potential drugs. In 2000, MacBeath cofounded Merrimack Pharmaceuticals in Cambridge, MA, to use systems biology to improve research on afflictions such as cancer. “This kind of work is going to change the way we discover drugs,” he says.