The FGFR1 gene provides instructions for making a protein called fibroblast growth factor receptor 1 (FGFR1). This protein is one of four fibroblast growth factor receptors, which are a family of proteins that are involved in processes such as cell division, regulation of cell growth and maturation, formation of blood vessels, wound healing, and embryonic development.~The FGFR1 protein spans the cell membrane, so that one end of the protein is inside the cell and the other end sticks out from the outer surface of the cell. This positioning allows the FGFR1 protein to interact with other proteins called fibroblast growth factors (FGFs) outside the cell and to receive signals that help the cell respond to its environment. When an FGF attaches to the FGFR1 protein on the outside of the cell, it starts a series of chemical reactions inside the cell that tell the cell to undergo certain changes or to learn new functions. This signaling is thought to play an important role in the development and growth of several parts of the body, including the brain, the bones in the head and face (craniofacial bones), the bones in the hands and feet, and the long bones in the arms and legs.~The FGFR1 protein plays a critical role in the formation, survival, and movement (migration) of nerve cells (neurons) in several areas of in the brain. In particular, the signals passed through this protein appear to be essential for neurons that produce a hormone called gonadotropin-releasing hormone (GnRH). GnRH controls the production of several other hormones that direct sexual development before birth and during puberty. These hormones are important for the normal function of the ovaries and testes. FGFR1 also appears to play a role in the processing of smells by a specialized group of neurons (olfactory neurons).