The surface of almost every human cell is covered by tiny hair-like structures – primary cilia. Their dysfunction leads to many disorders, including impaired growth. Pavel Krejčí’s team from the Institute of Animal Physiology and Genetics CAS and Masaryk University of Brno, in collaboration with their colleagues from the University of California in Los Angeles has taken a crucial step towards understanding the origins of serious growth disorders. This paves the way to finding possible treatment.