To further confirm that these genes are regulated by the TGFβ pathway, we performed in vitro cell culture experiments which showed that while TGFβ is able to activate COL1A1, CTGF, HAS1 and HAS2 gene expression in 4T1 mammary adenocarcinoma cells, pre-treatment with tranilast significantly inhibited TGFβ-mediated upregulation of COL1A1, CTGF and HAS2, but not HAS1 (Supplementary Fig. S7). This evidence concerns the gene COL1A1 and breast adenocarcinoma.