Macrophages are evolutionary ancient cells that are critical for maintaining tissue integrity by performing catabolic and anabolic reactions in tissues, and the disturbance of macrophage function can promote disease. Recent data indicate that macrophages use different metabolic programs to perform individual effector functions in vitro establishing the research area of immunometabolism. However, the role of metabolic signals and the cellular metabolism for macrophage function are multifaceted, complex, and largely unexplored in vivo. The immunometabolic crosstalk of macrophages with tissues remains largely unknown. A comprehensive understanding of the immunometabolic functions of macrophages and their communication with tissues in vivo will be of critical importance in determining how macrophages maintain tissue integrity and how they contribute to tissue dysfunction in diseases such as obesity, type 2 diabetes, colitis, cancer, or cachexia. The goal of the F83 SFB IMMUNOMETABOLISM is to reveal the in vivo relevance of metabolic reprogramming in macrophages for tissue function. We want to discover novel therapeutic approaches that target the metabolism and the metabolic signals of macrophages in human disease.