Notably, the mRNA levels of the mesenchymal markers SLUG, SNAI1, VIM, and NCAD were increased by ectopic GREM1 expression (Fig. 4c, d) or exogenous rhGrem1 treatment (Additional file 5: Figure S4b), suggesting that Grem1 induces a slightly more mesenchymal phenotype in these breast cancer cells. Here, SNAI1 is linked to breast cancer.