On Oct. 13, 2016, the Cell Atlas Initiative was launched at a meeting at The Wellcome Trust in London. Experts from around the world – convened by Wellcome, the Wellcome Trust Sanger Institute and the Broad Institute of MIT and Harvard – met to discuss how to shape the Human Cell Atlas.a collaborative community of world-leading scientists met in London 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.

The first project of its kind, and as ambitious in scope as the Human Genome Project – which catalogued the first full human DNA sequence – the Human Cell Atlas aims to chart the types and properties of all human cells, across all tissues and organs, to build a reference map of the healthy human body.

The meeting, convened by the Broad Institute of MIT and Harvard, Wellcome Trust Sanger Institute and Wellcome Trust, brings international experts together to decide on the elements of the first phase of the Human Cell Atlas initiative.

By making the Atlas freely available to scientists all over the world, scientists hope to transform research into our understanding of human development and the progression of diseases such as asthma, Alzheimer’s disease and cancer. In the future, the reference map could also point the way to new diagnostic tools and treatments.

The human body is made of trillions of cells – the fundamental units of life – which divide, grow and acquire distinct functions in the embryo, eventually leading to different cell types (such as skin cells, neurons or fat cells) that form the various tissues of the body. These tissues come together to form organs such as the lungs and the brain.

Previous knowledge of cells has come from looking at them under a microscope, or more recently by analysing clumps of hundreds or thousands of cells and finding the average properties. However, to see the true picture for every cell type, it is necessary to first separate the cells and then find out what molecules are produced in each. These molecules include sets of RNA messages, called the transcriptome, which help give each cell its own identity and distinguish it from the many other cell types found in the body.

A few years ago, measuring this complex and extensive information would have been impossible, but recent technological advances in the field of single-cell genomics can separate individual cells from different tissues and organs, and measure the transcriptome or other important molecules from each of them.