Joel H. Rubenstein, MD, MSc, co-author of new research on the synergistic effects of alcohol and tobacco consumption on the risk of esophageal squamous cell carcinoma talks with AJG Co-Editor Dr. Paul Moayyedi about the concept of synergy in epidemiological research, the potential confounding factors and variability of the studies included in the meta-analysis, and the explanations and implications of this synergistic effect of tobacco and alcohol on esophageal cancer. (16:10)