Being a receptor of Toll-like receptors (TLR) 4, lipopolysaccharide (LPS) can downregulate the pseudo-receptor of TGF-β1 [bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI)], resulting in activation of the transforming growth factor (TGF)-β1/Smad signalling pathway and mediating the epithelial-mesenchymal transition (EMT) of prostatic hyperplasia cells (He et al. The gene discussed is TGFB1; the disease is benign prostatic hyperplasia.