We found out for the first time that hepatic mRNA of both Abcb1a/Mdr1a and Abcb1b/Mdr1b genes, as well as protein content of ABCB1, was significantly decreased in fenofibrate-treated hypertriglyceridemic rats with moderate hepatic steatosis. The gene discussed is ABCB1; the disease is Hepatic steatosis.