Scientists now have the ability to create millions of new molecules. How do they test whether any of these molecules are useful? Focusing on a network of proteins involved in glucose sensing and type II diabetes, Dr. Schreiber explains two methods for screening small molecules. Small-molecule microarrays are used to screen for molecules that bind to specific proteins. In cell-based screening, proteins can be probed while performing their cellular jobs. Robotic automation and inexpensive computing have made these mass-scale parallel assays practical. Dr. Schreiber also discusses ChemBank, a project designed to gather information linking proteins, small molecules, and functions. He suggests that in the future, a synergy of chemistry, biology, and computational science may help scientists classify a host of small molecules that affect specific biological functions.