They demonstrated the crucial role played by TGF-β1 on the proliferative state of cancer cells, which acquired the stem cell phenotype for self-renewal, drug resistance, neoangiogeneiss, and tumorigenicity; on the contrary, blocking the TGF-β1 signaling pathway reduced the dedifferentiation program of osteosarcoma cells. The gene discussed is TGFB1; the disease is cancer.