Furthermore, in line with the fibroblast-specific expression of GREM1 and ISLR, analyses of The Cancer Genome Atlas and expression microarray data showed that the highest expression levels of GREM1 and ISLR were observed in a stroma-rich molecular subtype of CRC (consensus molecular subtype 4 [CMS4]) (Supplementary Figure 9A and B). Here, GREM1 is linked to colorectal carcinoma.