Tissue engineering, cell therapies and regenerative medicine have witnessed accelerated progress over the past decade. Fueled by fundamental discoveries in iPS, progenitor, and developmental cell biology, cells are now used as building blocks to create model systems, as testing platforms for drug interventions and as active therapeutics. High-throughput production of various types of “microtissues” or “organoids” is making increasing contributions to our understanding of human development, disease and repair. This Keystone Symposia meeting will highlight these rapidly emerging cell-based tools for fundamental and applied discovery. Culture systems ranging from simple cell cluster organoids, to highly advanced cell-electronic composites, will be discussed. In addition, the encouraging progress that is being made in cell-based therapies across a range of organs and diseases will be featured. The goal of this meeting is to provide a state-of-the-art review of both pluripotent and differentiated cells as tools for discovery and therapy. A broad range of cell types and therapeutic areas will be included.