Growth differentiation factor 5 （GDF-5）, also known as bone morphogenetic protein 14 （BMP-14）, is a member of the transforming growth factor beta （TGF-β） superfamily. It plays a crucial role in skeletal development and joint formation, as well as in the regulation of cell growth and differentiation. In mice, GDF-5/BMP-14 is essential for the proper development of bones, cartilage, and joints, and mutations in the GDF-5 gene have been associated with skeletal abnormalities and joint disorders. GDF-5/BMP-14 exerts its biological activities by binding to specific cell surface receptors and activating downstream signaling pathways that regulate gene expression and cellular functions involved in skeletal development and maintenance.