The URoL:MIM program defines a microbiome as a community of microorganisms with more than one type of organism, including bacteria, archaea, fungi, protists, and viruses that inhabit a particular habitat. The habitat can be a living host or a particular environment, broadly defined to include the biological, chemical, physical, and/or social state, settings, or conditions. The URoL:MIM Program is focused on the causal and mechanistic understanding of the structure and function of these microbiomes and the connections, interactions, and interdependencies within and among the microbiome, the host, and the environment (biological, chemical, physical, and social). The major objective of URoL:MIM is to develop an integrated understanding of how microbiome organisms communicate and interact with each other, with their hosts, and with their environments, across various spatial and temporal scales. This includes mechanisms underlying how the microbiome affects the phenotypes of organisms and their robustness, resilience, and adaptability. How the underlying relationships among the microbiomes, hosts, and physical, social, and built environments ultimately emerge as properties that affect phenotype of the microbiome, the host, or both is of interest. Full proposal deadline: February 23, 2021.