GREM1 and colorectal carcinoma: Overexpression of GREM1 was also shown to enhance the motility and invasion of CRC cells by epithelial–mesenchymal transition (EMT), as well as upregulating activating transcription factor 6 (ATF6) and downregulating ATF4, modulating the unfolded protein response through activation of PI3K/AKT/mTOR and antagonizing BMP2 signalling pathways [60].