ABSTRACT Support is requested for a Keystone Symposia conference entitled Host and the Environment in IBD: Scientific Advances Leading to New Therapeutics, organized by Drs. Gary D. Wu, Scott Snapper, Judy H. Cho and Aida Habtezion. The conference will be held in Taos, New Mexico from January 13-17, 2019. The inflammatory bowel diseases (IBD), which afflict millions of patients, are rapidly increasing in incidence world-wide in parallel with industrialization. Pathogenesis involves both host genetic as well environmental factors where the most currently utilized therapeutics focus on long-term host immunosuppression. Dramatic advances in genomics, transcriptomics, metabolomics, and proteomics, together with the development of increasing sophisticated biostatistical algorithms, have led to an increasingly sophisticated understanding of the complex interactions between the host immune system and the environment. Additionally, large prospective human cohort studies combined with new insights generated from the study of model organisms are providing new mechanistic insights into the regulation of the mammalian immune system and how it may become dysfunctional within the context of immune mediated disease processes such as IBD. However, despite these tremendous advances, currently available therapeutic modalities for IBD remain suboptimal. The overall goal of this meeting is to bring together world-class investigators and clinicians to discuss the latest scientific knowledge relevant to the pathogenesis of IBD to facilitate an interactive discussion about paradigms that will facilitate the accelerated development of new opportunities to prevent and/or treat IBD. The specific aims of this meeting are: 1) To bring together a combination of clinical and basic investigators from both academia and industry to facilitate cross-disciplinary discussions focused on IBD. 2) To identify both the opportunities and gaps in current knowledge in the pathogenesis of IBD important for the development of new diagnostics and therapeutics for IBD and 3) To create a multidisciplinary environment that will inspire both young and established investigators by highlighting the currently available opportunities in research focused on the field of IBD. The anticipated outcome of this meeting will be a better understanding of the advances, and the challenges, in the current field that will lead to new therapies for patients with IBD.