GREM1 and colorectal carcinoma: In contrast, using a cohort of CRC tissue sorted into purified pools according to their cellular lineages (GSE39396 [26]; endothelial, epithelial, leukocytes and fibroblasts), we now demonstrate that GREM1 mRNA levels are significantly associated with CAFs compared to other components of the TME (p< 0.0001; Figure 2A).