TGFB1 and neoplasm: Knockdown of Tgf-β1 by TGF-β1 specific small interfering RNA (siRNA) and neutralization of TGF-β1 by 1D11 antibody in 4T1/RFP cells showed an inhibitory effect on the invasion and TGF-β1 secretion of tumor cells (siRNA vs control, 0.46-fold difference, P = 0.01; 1D11 vs control, 0.31-fold difference, P = 0.003) (Fig. 5a, b and Additional file 6: Figure S4A, B).