Morale at the FDA plummeted when Crawford indefinitely postponed nonprescription sales of emergency contraception -- Plan B -- over the objections of staff scientists who had declared the pill safe.

President George W. Bush designated the National Cancer Institute's director, Dr. Andrew von Eschenbach, to be the FDA's new acting commissioner.

Crawford's resignation came just two months after the Senate, in a long-delayed move, elevated the longtime agency deputy and acting commissioner to the top job.

Increasing Criticism

His three-year tenure at FDA was marked by increasing criticism and a particularly rocky final 12 months. The painkiller Vioxx was pulled off the market for safety problems, FDA was embarrassed last fall when its British counterparts shut down a supplier of US flu vaccine for tainted shots, and over the summer recalls of malfunctioning heart devices mounted.

Finally last month, morale at the agency plummeted when Crawford indefinitely postponed nonprescription sales of emergency contraception over the objections of staff scientists who had declared the pill safe. FDA's women's health chief resigned in protest.

Still, Crawford's resignation, effective immediately, was a surprise. An affable veterinarian who specialized in food safety, he was elevated by Bush from acting commissioner to the full job in part because his experience was deemed important as the FDA tried to better safeguard the food supply against bioterrorism.

Make Cancer a Chronic Disease?

Von Eschenbach, tapped to be the FDA's acting chief, is a cancer survivor and urologic surgeon from Bush's home state of Texas, who was chief academic officer of the University of Texas MD Anderson Cancer Center before moving to the National Cancer Institute.

His tenure isn't immune from controversy either: Von Eschenbach has said that he hopes by 2015 to make cancer a chronic disease that patients can live with instead of die from. While a laudable goal, it's one that many oncologists caution that science isn't yet that close to achieving for most types of cancer.