A growing body of evidence links the microbiome, which can be altered by diet, with response to cancer immunotherapy. A more difficult task is teasing out the mechanism by which diet might be used to improve immunotherapy outcomes. “When we think of tumor response to immunotherapy, we traditionally think about the tumor and the tumor microenvironment,” said Jennifer McQuade, MD, University of Texas MD Anderson Cancer Center. “The role of the host has not been studied until quite recently. We can’t change host factors such as age and sex, but we can change diet. The microbiome has become a therapeutic target.” Dr. McQuade spoke Friday, April 8, during the Educational Session Diet, Microbiota, and Cancer Immunotherapies, which explored the links between dietary modification of the microbiome and response to immunotherapy. This session was part of the American Association for Cancer Research (AACR) Annual Meeting, which was held April 8-13 in New Orleans. This educational session and other meeting sessions can be viewed on the virtual platform by registered meeting participants through July 13, 2022. Registration can be done here. Over 19,000 scientists and physicians registered for this premier cancer conference, with ~80% (~15,200) attending in person and ~20% (~3,800) attending virtually. The AACR has over 50,000 members worldwide.