Andrew T. Chan, MD, MPH (Damon Runyon Clinical Investigator ‘08-‘13) of Massachusetts General Hospital, Boston, working with a multi-institutional team, analyzed data from two long-term studies involving nearly 128,000 participants. The researchers found that individuals whose colons have high levels of a specific gene, 15-hydroxyprostaglandin dehydrogenase (15-PGDH), dramatically reduce their chances of developing colorectal cancer by taking aspirin. In contrast, aspirin provides no benefit to individuals whose colons show low levels of 15-PGDH. This study will help physicians to determine which patients are likely to benefit from aspirin. The findings were published in the journal Science Translational Medicine and featured in The New York Times.