It was further demonstrated that this subset of cells with stem/progenitor are tumorigenic in damaged livers (i.e., in chronic injury and compensatory proliferation) and in this context the microenvironment, IL-6 and TGF-β signaling are required to promote in vivo growth and malignant progression of hepatic cancer progenitor cells and tumor metastasis [4]. The gene discussed is TGFB1; the disease is liver cancer.