The sterol response element(SRE)of the LDL receptor promoter is responsible for normal sterol regulation and the expression of LDLR gene.This regulation involves sterol regulatory element binding proteins(SREBP) and the SREBP cleavage activating protein(SCAP).A number of serum factors and hormones have been reported to regulate LDL receptor expression such as 3-hydroxy-3-methylglutaryl coenzyme A reductase(HMG-CoA reductase),hormones,Hepatocyte growth factor.