Scientists have created the first map of every cell in a pair of human lungs, giving hope of better treatment for millions of asthma sufferers.
The revolutionary 'atlas' will transform knowledge of the disease, according to the researchers who created it.
By comparing the cells to those of people with healthy lungs, scientists can better understand what causes the symptoms of asthma including coughing, wheezing and shortness of breath.
It has already led to an entirely new discovery of how cells produce more mucus in asthmatics.
Asthma affected more than 350million people worldwide in 2015. In the UK it blights the lives of one in 11 children (1.1million) and one in 12 adults (4.3million).
The mapping of the lungs is part of a global project that started in 2016 called the Human Cell Atlas Initiative.
Over the next decade the team plans to discover how many cells people have, in their entire bodies, the different types and what they do in each organ.
