The use of programmable nucleases such as CRISPR-Cas systems, ZFNs and TALENs has revolutionized cell biology by providing the ability to manipulate specific genetic and epigenetic states within living cells. These systems have been broadly applied as tools in research settings and increasingly are being developed to create improved models of disease and engineer cells for therapeutic purposes. Together with other DNA modifying systems such as recombinases, integrases and transposases, it is now possible to introduce mutations that will model human disease, build complex synthetic signaling networks to perform regulated functions and design cells to target specific disease states. Improvements to the methods involved requires understanding enzyme structures and mechanisms and how they intersect with cellular DNA repair systems. The intersection of this basic science with engineering approaches and improved cellular models is revolutionizing our understanding and treatment of human disease. The goal of this Keystone Symposium is to bring together people developing and studying genome engineering tools with groups who are applying them to build new disease models, identify disease mechanisms and drug targets, and develop cell-based therapeutics and genetic medicines. In addition to covering engineering of human and animal cells, this meeting will also highlight the emerging field of genome engineering to identify new anti-microbial and anti-viral drugs and applications towards next generation antibiotics. Invited talks will explore a broad range of topics covering new technologies, fundamental basic research, through the development of screening approaches, stem cell-based models of disease and design and development of cellular therapeutics.