The Human Cell Atlas is an international collaborative research consortium that is mapping all cell types in the healthy body, across time from development to adulthood, and eventually to old age. The global HCA community has profiled tens of millions of cells from nearly 10,000 individuals and produced more than 190 HCA scientific publications so far, yielding fundamental insights into human biology and its malfunctions in disease. The HCA is producing a healthy reference map, like a ‘Google Maps’ for the human body, which can be compared with disease to understand illnesses, or serve as a blueprint for developing molecular and cell therapies.