TGFB1 and neoplasm: Thus, while it is possible that the administered RER might neutralize TGF-β signaling in both stromal and epithelial cells in the prostate, our results appear to indicate that RER might have blocked TGF-β signaling much more severely in the stromal cells than in the epithelial cells resulting in a moderate blockade of tumor progression by reducing various growth factors produced by stromal cells as we have reported previously [41].