AXIN1 and osteosarcoma: The osteosarcoma cell line 143B, despite the lack of sensitivity (up to 30 μmol/L) to SEN461 treatment in the soft agar assay, showed Axin1 stabilization and down-regulation of total level of cytoplasmic β-catenin (Figure 2D), arguing that either the cell line is Wnt-independent or additional genetic/epigenetic alterations drive the growth and therefore consequently the insensitivity to SEN461.