E-cigarettes have increased in prevalence over the past decade and provided a powerful alternative to tobacco products like cigarettes. E-cigarettes have the potential to be addictive in part because qualities that are typically inherent to a substance (e.g., flavor, "harshness") can actually be modified to increase the reinforcing efficacy of the nicotine from the e-cigarettes. However, the full picture of both acute and chronic consequences are yet to be understood.  Dr. Adam Leventhal provides an overview of the science of e-cigarettes and vaping, including what we now about it's harm and addictive potential. He also discusses his work regarding the regulation "sweet spot": making it appealing enough for cigarette smokers to want to start using e-cigarettes, but aversive enough to prevent uptake among at-risk groups, such as adolescents. He also discusses how to develop a research career that has a focus on public health impact. Dr. Adam Leventhal is a Professor in the Department of Preventive Medicine and Psychology in the Keck School of Medicine at the University of Southern California. He is also the Director of the USC Institute for Addiction Science and Health, Emotion & Addiction Laboratory; a new Fellows Chair in the APA Division on Psychopharmacology and Substance Abuse (Division 28); and a recently appointed member of the Tobacco Products Scientific Advisory Committee for the Food and Drug Administration.