Chondrogenesis, the formation of cartilage, is important for the biological processes of endochondral bone formation, skeletogenesis, and tissue patterning. This dynamic cellular event results in the formation of hyaline, fibrous, and elastic cartilage. Chondrocytes, which differentiate following the condensation of mesenchymal stem cells, are responsible for the secretion of extracellular matrix molecules, such as collagens and proteoglycans. Transcription factor SOX9 is critical for chondrocyte differentiation and function. The importance of SOX9 in chondrogenesis is underlined by the fact that heterozygous mutations in the SOX9 gene result in a severe skeletal malformation syndrome called campomelic dysplasia. Although cartilage tissue is frequently subject to damage by trauma and disease, it has little capacity for repair, making this process an area of focus for tissue engineering research.