Y Zheng

Every morning the city wakes up and starts repairing itself: workers replace asphalt, painters coat facades, street sweepers haul away trash. You can picture skin as just such a city, where worker cells constantly renew the streets and buildings.

Human tissue is like a city: dense neighborhoods of specialized cells, streets of blood vessels, plazas of functional units. As we age, this city gets remodeled. Researchers from the GTEx project examined 14,788 tissue sections from 980 donors and segmented 3.5 billion cells across 16 organs to see how this architecture changes.