Collectively, these observations indicate that TGF-β1-driven EMT is responsible for the migration of tumor initiating cells by directly linking the acquisition of neoplastic cellular motility with the maintenance of malignant proliferation potency; thus, metformin-mediated TGF-β1 downregulation may be responsible for suppressed migration, proliferation, abnormal malignant cell invasion and EMT changes [55,56]. The gene discussed is TGFB1; the disease is neoplasm.