Component of the TLR4 signaling complex. Mediates the innate immune response to bacterial lipopolysaccharide (LPS) leading to cytokine secretion and the inflammatory response (By similarity). Belongs to the lipopolysaccharide (LPS) receptor, a multi-protein complex containing at least CD14, MD-2 and TLR4. Interacts with TLR4; this interaction is greatly enhanced following LPS stimulation (By similarity). Interacts with LPS (By similarity). Highly expressed in cortical astrocytes and in cerebellar granule neurons. N-glycolysaled.