TLR4 and familial hypercholesterolemia: Intimal smooth muscle cells surround and penetrate early lesions, where TLR4 signaling, enhanced by hypercholesterolemia, promotes lesion progression by stimulation of acyl-coenzyme A: cholesterol acyltransferase-1 mRNA expression, cytoplasmic cholesterol ester accumulation, and monocyte chemoattractant protein-1 (MCP-1) mRNA and protein expression in a TLR4-dependent manner.