SOX9 and chondrosarcoma: In the absence of other ROCK substrates than SOX9, a ROCK-dependent increase in nuclear SOX9 in TGF-β1 treated knee AC hCHs in an alginate hydrogel and a dose-dependent induction of SOX9 transcriptional activity by ROCK have been demonstrated in vitro in SW1353 chondrosarcoma cells in a monolayer culture on plastic [303], supporting the notion that one would expect high phosphorylated SOX9 levels to be associated with high ROCK activity.