Interestingly, we found that the effect of addition of TGF-β1 and Hsp90β on AIG is opposite in the two cell lines in that the exogenous addition of each of these proteins inhibits the formation of tumourspheres in SW480 primary tumour-derived cells, but has either no effect (in the case of TGF-β1) or stimulates tumoursphere formation (in the case of Hsp90β) in the SW620 metastasis-derived line. This evidence concerns the gene HSP90AB1 and neoplasm.