Can a human organ be mapped on a single-cell level to learn more about each individual cell? And can we learn how different these cells are from person to person? Helmholtz Munich researchers and their collaborators have taken up this challenge and developed the Human Lung Cell Atlas using artificial intelligence (AI)-based techniques. This atlas elucidates the diversity of single lung cell types and allows learning about lung biology in health and disease. It is the first major integrated organ and was built as part of the Human Cell Atlas (HCA) initiative, a worldwide collaborative effort to map the entire body at the level of single cells. The results were published in Nature Medicine.