ATF4 and neoplasm: Previous studies have shown that EMT in a variety of tumor cells is inextricably linked to the activation of ERS, which could be seen in our study that the canonical ER stress chaperone and sensors Bip, ATF6 and IRE1a were upregulated whilst ATF4 was downregulated at the mRNA and protein expression levels in GREM1-overexpressing HCT116 and SW480 cells (Figure 2I–K).