sentences:  Thus TGF-β signaling involves a direct pathway from the receptors on the surface of a cell to the nucleus.Toll-like receptors (TLRs) are signaling PRRs, capable of recognizing various bacterial proteins.Although bacteria have evolved means of evading host defense mechanisms, they express PAMPs, such as lipoglycans and lipoproteins that are recognized by cells of the innate immune system through the TLRs.