There are several types of TLRs, each recognizing distinct ligands. For instance, TLR4 recognizes lipopolysaccharides (LPS) from Gram-negative bacteria, while TLR3 recognizes double-stranded RNA (dsRNA) from viruses. Other examples include TLR2, which can form heterodimers with TLR1 or TLR6 to recognize peptidoglycans and lipopeptides.
