Toll-like receptor 4 (TLR4)

Toll-like receptor 4 (TLR4) is a protein found on immune cells that helps the body recognize harmful threats like bacteria. When TLR4 detects components of bacterial cells, such as certain fats, it triggers the immune system to respond by activating inflammation and other defenses. This process is crucial for fighting infections but must be carefully controlled to avoid excessive inflammation, which can lead to disease. TLR4 is an essential part of the body's innate immunity, acting as a first alert system to defend against invading microbes.