TLR4 (Toll-like receptor 4) is a key protein involved in the innate immune system, specifically recognizing lipopolysaccharides (LPS) found on the outer membrane of Gram-negative bacteria. Activation of TLR4 leads to the initiation of pro-inflammatory responses and the production of various cytokines that play a role in the immune response. Research in the area of TLR4 focuses on understanding its role in immune responses, inflammation, and potential therapeutic targets for infectious diseases, autoimmune disorders, and other conditions. Additionally, dysregulation of TLR4 signaling has been implicated in various inflammatory diseases and cancers, making it a promising target for drug development.