Toll-Like Receptors (TLRs) are proteins found on the surface of certain immune cells. They play a crucial role in the body's defense system by recognizing pathogens like bacteria and viruses. When TLRs detect these harmful invaders, they trigger an immune response, helping the body to fight off infections. TLRs are part of the innate immune system, which is the body's first line of defense. They help identify common features of pathogens, known as pathogen-associated molecular patterns (PAMPs). This recognition leads to the activation of immune cells and the production of signaling molecules, enhancing the overall immune response.