Located in the perisinusoidal space of Disse, hepatic stellate cells (HSCs) communicate with all other liver cell types by physical association and / or by producing cytokines and chemokines. In liver disease and folllowing liver transplantation, elevated levels of endotoxin (bacterial lipopolysaccharide: LPS) stimulate HSCs to produce increased amounts of cytokines and chemokines. Transcriptomic analysis of cultured HSCs stimulated with LPS yields a survey of expression changes which potentially modulate the hepatic inflammatory and immune responses. Overall design: In two independent experiments, rat HSCs were cultured with or without 10 ng/ml LPS for 1h and 24h, then harvested for microarray analysis (i.e., 8 samples). In the first of these experiments, cells also were also harvested after 3, 6 and 12 hours of LPS treatment, for a total of 11 samples.