Osteocytes are cells inside the bone capable of sensing pressures or cracks in the bone. These cells also come from osteoblasts – cells that form a new bone. They control how other types of cells make or break down parts of the skeleton to maintain strong and healthy bones. Recently, the genetic profile of these cells was mapped for the first time. The new research identifies the genes that are switched on or off in osteocytes. It will help diagnose genetic diseases that affect bones.