IL-6 up-regulates soluble MD-2 production and secretion by HepG2 cells. HepG2 cells were stimulated with IL-6 for 3, 6, 12, 24, and 48 hours. Western-blot of sMD-2 in HepG2 supernatants (23 kDa), MD-2 in HepG2 cell lysates (17, 23, 25 kDa), and α-actin as a loading control. This experiment is representative of 3 different experiments.