TGFB1 and carcinoma: Therefore, for tumor cells capable of undergoing hysteretic EMT, a short duration of exposure to TGF-β produced by tumor stromal cells, such as carcinoma associated fibroblasts (CAFs) or platelets, during invasion and dissemination may be sufficient to commit the disseminated tumor cells (DTCs) to EMT, and facilitate extravasation and early seeding of cancer cells at distant organs to promote metastasis formation.