John is the University of Wisconsin, Epigenetics Theme Director of the Wisconsin Institute for Discovery, and Professor of Biomolecular Chemistry. His laboratory focuses on the roles of reversible protein modifications, in particular histone modifications, that are involved in modulating signal transduction, chromatin dynamics, and gene expression. John is a key opinion leader in the field of small molecule sirtuin modulators; his lab has both discovered small-molecule ligands and significantly advanced the field from early controversies to the molecular elucidation of mechanisms of action for a synthetic, natural product, and in vivo agonists of multiple family members of sirtuins. John is a Fellow of the AAAS and has received numerous honors including the American Cancer Association Young Investigator and Research Scholar Awards, and the NIH Merit Award.