For more than two years, Stephen Hahn has helped to run one of the world’s leading cancer research and treatment centres, steering it through a financial crisis and a scathing government report on safety lapses at one of its facilities. On 5 November, US President Donald Trump nominated the radiation oncologist to lead the Food and Drug Administration (FDA). The Senate has yet to confirm Hahn, who is currently the chief medical executive of the University of Texas MD Anderson Cancer Center. If it does, Hahn could bring welcome stability to the agency as it faces an onslaught of challenges.

The agency is at the centre of a national debate over e-cigarettes, prompted by a mysterious vaping-related illness that has made more than 2,000 people sick — 39 of whom have died. As a result, lawmakers are questioning the FDA’s lenient regulation of the burgeoning industry. The United States is also in the grips of an epidemic of prescription-opioid abuse , with open questions as to how best to treat those who have become addicted and how to prevent others from following in their footsteps. On top of all of this, the FDA is dealing with the recent discovery of a suspected cancer-causing compound in some widely used medicines — which have since been recalled — for treating blood pressure, heart failure and heartburn.

But the biggest challenge for Hahn will be navigating a regulatory agency during an anti-regulatory administration, says former FDA chief Robert Califf . Trump took office pledging to roll back regulations, and has done so across government agencies, particularly at the Environmental Protection Agency.

Prepare for a grilling

If Hahn is confirmed to lead the FDA, he will become the agency’s fifth leader — three of whom were interim heads — since the start of Trump’s administration in 2017, bringing some welcome stability. “Confirmed commissioners are needed to have a voice with authority to implement sustainable strategies,” says Califf.

In some respects, Hahn’s nomination is likely to be less controversial than that of the last confirmed head, physician and businessman Scott Gottlieb , who ran the FDA from May 2017 until his resignation in April. Gottlieb had served on the boards of multiple pharmaceutical companies and worked as a venture capitalist.

Hahn, in contrast, has far fewer industry ties. He received roughly US$1,000 in non-research industry funds in 2017, the latest year for which data are available. Those funds were used for travel and lodging, and put him well below the nearly-$4,000 average for his specialty.

But the confirmation hearings in the Senate could still be a battle, cautions Califf, and Hahn can expect a grilling about how he will handle e-cigarette regulation. “Vaping looks treacherous right now,” says Califf. “The Congress will be split, and so there is no right answer that will assuage everyone.”