Tumor stem cells are responsible for metastasis and relapse of cancer.Transforming growth factor-β1 (TGF-β1) plays an important role in the proliferation and differentiation of tumor stem cells.In many cancers such as breast carcinoma,hepatocellular carcinoma,pancreatic carcinoma,lung carcinoma,glioma and gallbladder carcinoma,the epithelial-mesenchymal transition (EMT) induced by TGF-β1 can inhibit proliferation of cancer cell,enrich tumor stem cells and increase invasive capability and drug resistance of cancer.