Use of a Vitamin A derivative in former smokers restored production of a crucial protein believed to protect against lung cancer development, researchers have found. Although they don’t have clear evidence that the three-month therapy using 9-cis retinoic acid (9-cis-RA) restored health to cells that were already precancerous, the researchers say the work demonstrates that “chemoprevention” of future lung cancer may be feasible. “The drug we used acts to reverse a genetic abnormality associated with development of lung cancer,” says Jonathan Kurie, M. D., an associate professor of medicine at the University of Texas M. D. Anderson Cancer Center. “The work is a proof of concept, suggesting that compounds like this may prove to have a protective effect against development of precancerous lesions.”