ABSTRACT Support is requested for a Keystone Symposia conference entitled Tumor Metabolism, organized by Drs. Eileen P. White, Joshua D. Rabinowitz, Marcia C. Haigis and David M. Sabatini. The conference is anticipated to be held in Banff, Canada from February 6-10, 2022. The field of tumor metabolism is one of the oldest in cancer biology, dating back to the seminal work of Otto Warburg in the 1920s. Clinical importance of tumor metabolism is well validated by the successes both of FDG-PET imaging and of antimetabolites as chemotherapeutic agents. The recognition that oncogenes both promote the Warburg effect and activate anabolic pathways has provided impetus for revitalized examination of tumor metabolism. This conference brings together leaders in tumor metabolism to discuss ongoing efforts to understand and target metabolism of proliferating cancer cells and their support network. This conference will address key questions regarding the metabolism of proliferating cells, the unique metabolic features of tumors in vivo, and the associated opportunities for therapeutic intervention, including at the interface between metabolism and immunotherapy. Key scientific questions that conference session will cover include (1) which features of cancer cell metabolism are shared across proliferating cells, and which are cancer specific? (2) how does signaling drive metabolism, and how does metabolism impact signaling and cell fate decisions? and (3) what are the dependencies of tumors on host metabolism, and what is the impact of tumor metabolism on host cells, including invading lymphocytes? By holding this meeting jointly with the Keystone meeting on “Immunometabolism at the Crossroads of Obesity and Cancer” we aim to synergistically address how overnutrition, the microbiome, and the metabolism of immune cells in the tumor microenvironment influences that anti-cancer immune response. Through discussion of these and other questions, the conference aims to generate new scientific ideas, promote collaborations, and enhance dissemination of the latest technologies and best practices for metabolic studies. As the premier venue sharing important unpublished data in the tumor metabolism field, this conference will help to accelerate scientific discovery and the development of new strategies to treat cancer.