After completing her postdoctoral training at the
Dana–Farber Cancer Institute (1988), she held a non-tenure track instructor position at Dana–Farber Cancer Institute and Harvard University (1988-1989). Piwnica-Worms joined the faculty at
Tufts University School of Medicine (1989-1992). In 1994, she moved to
Washington University in St. Louis (WashU) who were recruiting experts in cell cycle control. She was subsequently appointed the Gerty T. Cori Professor and Chair of Cell Biology and Physiology and Professor of Internal Medicine, and served as the associate director of Basic Science at the
Alvin J. Siteman Cancer Center. As such, she began testing ways to use CHK1 inhibitors to stop damaged cells from dividing. As a result of her research, Piwnica-Worms was promoted to head of the Department of Cell Biology and Physiology at Washington University School of Medicine in 2011. In 2013, Piwnica-Worms was recruited to join the
MD Anderson Cancer Center as their vice provost of science and professor in MD Anderson's Department of Cancer Biology. During this time, she was also elected a member of the
National Academy of Medicine for advancing the understanding and treatment of cancer. In 2019, Piwnica-Worms and her research team discovered that triple-negative breast cancer cells could develop resistance to frontline, or neoadjuvant, chemotherapy by transiently turning on molecular pathways that protect the cells. ==Personal life==