WNT5A and osteosarcoma: Table 2 summarises the results of all comparisons made. There is a large overlap of 1725 genes in osteosarcomas vs MSCs and osteosarcomas vs differentiated osteoblasts (DO). One gene that was significantly less expressed in osteosarcoma was WNT5A. This gene, involved in non-β-catenin Wnt signalling (Kuhl et al, 2000), has been tested with quantitative RT–PCR on the same series of RNA that has been used on microarrays as an alternative method to verify array data. The correlation between qPCR and array data was good, that is, 92% (Figure 4).