We found that expression of the chondrogenic master regulator gene, SOX9, was strong in enchondromas and significantly diminished in grade 1 chondrosarcomas, while expression of the cartilage-specific collagen gene, COL2A1, was dramatically decreased in grade 2 chondrosarcomas (Fig. 1c,d,e). This evidence concerns the gene SOX9 and chondrosarcoma.