Mapping cells to build a complete atlas of the human body

BODIES ARE made of cells. Lots of them. An average adult human contains about 37.2trn cells, 100 times as many as the number of stars in the Milky Way. Clearly, trying to map the location of every one of these cells would be a futile endeavour. But cells are not identical. They are divided into many types, each specialised for different tasks. Mapping the location of each of these types is a more tractable problem. And that is the objective of the Human Cell Atlas project, a collaboration of res...