Considering that recently GREM1 has been identified as a marker of mesenchymal stem cells in the bone marrow that can generate bone, cartilage, and the periepithelial intestinal mesenchymal sheath [20], it is also possible to hypothesize that GREM1-expressing myofibroblasts in the scar tissue and the cancer stroma originate from GREM1-positive mesenchymal stem cells in the bone marrow upon tissue destruction either by cancer invasion or inflammation. This evidence concerns the gene GREM1 and cancer.