Past randomized clinical trials have shown that non-steroidal anti-inflammatory drugs (NSAIDs), including naproxen, can reduce the risk of colon cancer and precancerous polyps in humans. Now, researchers have found that an investigational form of naproxen, called nitric oxide-donating naproxen (NO-naproxen), can block one of the earliest molecular changes that lead to colorectal cancer development while also reducing gastrointestinal toxicity, a relatively common side effect associated with NSAIDs.