Ongoing work in the Perrimon laboratory can be subdivided into four categories. First, to facilitate Functional Genomic approaches in Drosophila, they develop, improve, and generate reagent resources and bioinformatics tools. Second, they apply these tools to tissue culture cells and in vivo to elucidate the organization of the core Cell Circuitry networks involved in signaling and development. Third, as a model of Tissue Homeostasis, the lab studies the mechanisms that control the proliferation and differentiation of Drosophila adult gut intestinal stem cells (ISCs) in both normal and injured conditions. Fourth, as stability of large and complex biological systems depends on long distance communication between organs, they are dissecting the Inter-organ Communication Network, identifying new hormonal systems and determining their physiological roles and regulation.