COL1A1 and Osteoblastoma: Analysis of gene expression using qPCR revealed that osteogenic and chondrogenic differentiation related genes (COL1A1, COL2A1, RUNX2, BGLAP, OPN, SPARC) were only very lowly expressed in the cell lines before and after treatment, in comparison to the normal cartilage, growth plate and osteoblastoma controls (Figure 6A).