In London on 13 and 14 October, 2016, a collaborative community of world-leading scientists met and discussed how to build a Human Cell Atlas—a collection of maps that will describe and define the cellular basis of health and disease.

Cells are the most fundamental unit of life, yet we know surprisingly little about them. They vary enormously within the body, and express different sets of genes. Without maps of different cell types and where they are located in the body, we cannot describe all their functions and understand the biological networks that direct their activities.

A complete Human Cell Atlas would give us a unique ID card for each cell type, a three-dimensional map of how cell types work together to form tissues, knowledge of how all body systems are connected, and insights into how changes in the map underlie health and disease. It would allow us to identify which genes associated with disease are active in our bodies and where, and analyze the regulatory mechanisms that govern the production of different cell types.

This has been a key challenge in biology for more than 150 years. New tools such as single-cell genomics have put it within reach. It is an ambitious but achievable goal, and requires an international community of biologists, clinicians, technologists, physicists, computational scientists, software engineers, and mathematicians.

A White Paper, openly available for download, provides an overview of the effort; our framework for the first draft of the atlas; descriptions of the technology and data analysis tools available to build the atlas; an introduction to the Data Coordination Platform that will host the data for researchers worldwide; a deeper look at biological systems we plan to explore and map; and details on the organization and governance of the HCA consortium and its relationships to the public (including ethical considerations regarding organ and tissue donors) and to funding support.