Mammalian genomes are folded in a hierarchy of compartments, topologically associating domains (TADs), subTADs, and looping interactions. As genome-wide chromatin architecture maps become widely available, the field is shifting focus from mapping to understanding the dynamics of such structures in development, the cell cycle, and on short time scales in single cells. A critical emerging goal will be to unravel the cause and effect relationship between genome folding and functions such as transcription, replication, recombination, and stability/maintenance. There is also a great need to evaluate the organizing principles governing chromatin topology across many biological conditions and genetic perturbations. Moreover, the role for 3D genome misfolding in the onset and progression of a wide range of human disease states remains an area of high interest across multiple disciplines and organ systems. The conference program will also include workshops on: (1) Leading computational methods to identify biologically relevant patterns in Hi-C data, (2) New genome mapping and imaging technologies, and (3) New data resources available through the 4D Nucleome consortium. Finally, we will conclude with a session devoted to novel tools for imaging and engineering the 3D genome. Overall, the 2020 Keystone meeting is meant to highlight new frontiers across disciplines in tackling the dynamics and functional roles of the 3D genome in cellular functions across time and space in development and disease.