Soluble MD-2 secreted by HepG2 cells is bioactive. TLR4-HEK293 cells were stimulated with LPS (filled bars) or not (empty bars) in the presence of supernatants from HepG2 cells stimulated for 24 hours with IL-6 (10 ng/mL) and dexamethasone (10 μM). In some conditions, the 18H10 anti-huMD-2 blocking monoclonal antibody (α-MD-2) was added to cell cultures. IL-8 production by TLR4-HEK293 cells was measured in conditioned supernatant by ELISA. Bars correspond to mean values of 5 independent experiments performed in duplicate. Values are expressed as mean plus or minus SEM.