A Duke University cancer scientist whose research was recently questioned has resigned.
University spokeswoman Debbe Geiger said Dr. Anil Potti stepped down Friday as an associate professor of medicine at the school.
Geiger says another researcher at the school is asking the journal Nature Medicine to retract a paper he published with Potti, saying some of the tests in the research can not be duplicated. Other papers are also under review.
Some of Potti's research concerned gene patterns that might help predict a breast cancer patient's response to chemotherapy.
Geiger says three clinical trials based on Potti's research have been closed.
A phone message left at a listing for Potti was not immediately returned.