The second phase of NIH Common Fund 4D Nucleome Network Organizational Hub Abstract The second phase of the 4DN program requires an efficient organizational center to synergize the activities of all the funded teams and integrate the research products. Accordingly, the 4DN Organizational Hub is proposed to: (1) coordinate and integrate the efforts of all the funded projects, (2) build an efficient consortium infrastructure to serve as a center for the collaborative efforts, and (3) provide the 4DN web portal as a central resource gateway to access all the 4DN-Network generated tools, policies, guidelines, protocols, reagents, cell lines, and as a central hub for the outreach activities. Our major deliverables are: (1) an organizational structure composed of a steering committee and problem-solving working groups with a clear report chain to enable effective communications and decision-making processes, establish co-organizers and schedule, clarify action items, and ensure execution of the action items; (2) 4DN Web Portal (https://www.4dnucleome.org/), which is the always up-to-date community-wide resource and point of access for all data, protocols, reagents, resources, and methods; (3) 4DN internal wiki, the central organized resource for all teams, centers, and working groups to document internal progresses. (4) 4DN annual meetings, including the "kick-off" meeting in winter 2020 and the subsequent annual meetings and 4DN-ASCB (American Society of Cell Biology) satellite meetings; (5) 4DN outreach workshops at Keystone symposia and American Society of Human Genetics (ASHG) meetings, and on 4DN YouTube channel.