Previous publications indicate that some of the genes directly regulated by TGF-β can also be targets of KLF17.34, 35 To investigate the role of KLF17 in TGF-β/Smad-mediated signaling, we manipulated expression of KLF17 by RNA interference (RNAi) in cancer cell lines and tested TGF-β responsive SBE-containing luciferase reporter (SBE-Luc) activities. The gene discussed is TGFB1; the disease is cancer.