TLR3 is a type of protein known as a Toll-like receptor, which plays a crucial role in the immune system. It is primarily found on the surface of certain immune cells and helps detect viral infections by recognizing specific components of viruses, such as double-stranded RNA. When TLR3 binds to these viral components, it triggers an immune response to help the body fight off the infection. In addition to its role in detecting viruses, TLR3 is also involved in regulating inflammation and the overall immune response. By activating various signaling pathways, it helps coordinate the actions of other immune cells, ensuring a robust defense against pathogens. Understanding TLR3 is important for developing new treatments for viral infections and autoimmune diseases.