Cells with high ALDH1A1 levels have increased expression levels of vimentin, matrix metalloproteinase-2 (MMP2), MMP7 and MMP9, which are implicated in epithelial–mesenchymal transition and metastatic capabilities.40 Interestingly, CSN6 is able to promote the expression of ALDH1A1, a known CSC marker upregulated in cancer spheroids.41 Chromatin immunoprecipitation assays have characterised ALDH1A1 as a direct target of β-catenin activation. The gene discussed is MMP9; the disease is cancer.