It doesn’t always feel like it, but the U.S. Food and Drug Administration's (FDA) Center for Tobacco Products (CTP) is still a relatively new entity. It was established as part of the 2009 Family Smoking Prevention and Tobacco Control Act and signed by then-President Obama—meaning 2017 marked the first time that a CTP director from one presidential administration was tasked with working with an FDA commissioner from another.

The eras in which CTP Director Mitch Zeller and FDA Commissioner Dr. Scott Gottlieb entered the FDA are hardly the only differences between the two: Prior to his CTP appointment, Zeller worked on anti-smoking campaigns with the American Legacy Foundation, whereas Gottlieb served as director of a vaping company; Zeller has tended to side with tobacco control advocates, while Gottlieb has lobbied for tobacco harm reduction; and analysts and advocates alike have generally viewed Gottlieb as more pro-business in his approach to regulation than Zeller has been.

Though the FDA commissioner has historically given full purview of regulating tobacco to the CTP director, Gottlieb is officially Zeller’s boss. That begs a big question: Who will lead tobacco regulations moving forward?

Take a look at Zeller and Gottlieb’s histories and where they stand on a number of tobacco-related issues.