SOX9 and osteosarcoma: Additionally, using rat chondrosarcoma cells (RCS) and COS7 cells, the study [304] demonstrated that parathyroid hormone-related protein (PTHrP) also increased the phosphorylation of SOX9 at S181 through PKA in a dose- and time-dependent manner, whereas [305] demonstrated in that, in human CHs from healthy cartilage obtained from osteosarcoma or soft tissue sarcoma-related amputates, PTHrP induces SOX9 mRNA expression.