How do our cells organize themselves to give their final shape to our organs? The answer lies in morphogenesis, the set of mechanisms that regulate their distribution in space during embryonic development. A team has just made a surprising discovery in this field: when a tissue curves, the volume of the cells that compose it increases instead of decreasing. This discovery opens new avenues for in vitro organ culture, a partial alternative to animal experimentation. It also suggests new perspectives for the production of certain materials.