Chemistry can add a powerful dimension to the study of biological systems. Small molecules, peptides, proteins, polymers, and biocompatible materials have enabled IPiB faculty at UW-Madison to interrogate biological molecules, cells, and multicellular organisms spatially, temporally, and reversibly. Chemical Biology on the UW-Madison campus has a rich history that extends back to the Enzyme Institute and has been fueled by an on-going NIH training grant program (Chemistry and Biology Interface Training Grant) funded since 1993, as well as the establishment of a cluster hire initiative in chemical biology across campus.