Articular cartilage enables weight bearing and near friction-free movement in the joints.
Critical to its function is the production of a specialized, mechanocompetent extracellular
matrix controlled by master regulator transcription factor SOX9. Mutations in SOX9 cause
campomelic dysplasia, a haploinsufficiency disorder resulting in severe skeletal defects and
dwarfism. Although much is understood about how SOX9 regulates cartilage matrix
synthesis and hence joint function, how this master regulator is itself regulated remains …