As the phenotype of procollagen 11A1+ “myofibroblasts” from colon adenocarcinoma resembles that of cultured TGF-β1-activated human bone marrow mesenchymal cells, all these observations add support to the tenet that at least some cancer-associated stromal cells, such as the procollagen 11A1+ ones, could be bone marrow-derived mesenchymal cells. The gene discussed is TGFB1; the disease is colon adenocarcinoma.