The overarching goal of the Boston Human Tumor Atlas Network Research Center (HTA-RC) is to create three comprehensive atlases of the cellular geography of human melanoma, colorectal cancer, and breast cancer, to understand how changes in the tumor ecosystem lead each to therapeutic resistance. The atlases will map the topography of the number, nature, and spatial relationship of cells and histological structures that distinguish those tumors resistant to targeted and immune-based therapies. The Administrative Core will be responsible for the leadership, governance, and accountability of the Boston HTA-RC. The Core will coordinate and evaluate each component of the Research Center (RC); provide operational oversight of all aspects of the program; and monitor progress toward milestones. In particular, the Core will Provide overall management and coordination of RC activities (Aim 1). It will monitor progress toward the milestone goals, oversee financial expenditures, and provide support for all facets of the Center's activities, through: liaising closely with the Center's leadership and unit leads; project management and fiscal oversight; and on-going guidance from a local steering committee comprising domain experts in relevant fields. The core will also provide logistical support and facilitate communication within and outside the RC (Aim 2), to ensure dynamic interaction between all elements of the Center. A project manager will oversee flow of information, physical samples, and technologies between Units, leveraging both state-of-the-art electronic tracking systems, live and transparent aids, and active interaction through regular leadership meetings, steering committee meetings, an external advisory board, and an annual retreat. The Boston HTA-RC will be deeply embedded in the vibrant clinical and scientific communities at DFCI, Broad, and Massachusetts General Hospital (MGH), Harvard, and Stanford, and the Core will also be responsible for communication with the broader HTA network, the Data Coordinating Center, and the NCI. Finally, the core will evaluate progress toward milestones (Aim 3), based on a series of quantitative milestones we developed. It will assess milestone progress on a regular basis, provide reports to the Leadership Team, and develop proposals for any blocking issues or milestone revisions needed for discussions with NCI Program Officials.