Douglas R. Lowy is the current Principal Deputy Director of the U.S. National Cancer Institute (NCI) and Chief of the Laboratory of Cellular Oncology within the Center for Cancer Research at NCI. Lowy served as Acting Director of NCI between April 2015 and October 2017 following the resignation of Harold E. Varmus, M.D., and again between April and November 2019, while Director Norman Sharpless served as the Acting Commissioner of the U.S. Food and Drug Administration. He resumed the role of Acting Director on May 1, 2022, when Sharpless stepped down until October 3, 2022 when Monica Bertagnolli was appointed Director. He resumed the role again in November 2023 after Bertagnolli resigned to serve as director of the National Institutes of Health.