Homozygous knockout of scavenger receptor class B type I (SR-B1) in mice with atherogenic mutations (such as knockout of the apolipoprotein E or low density lipoprotein receptor genes) results in spontaneous or diet-induced coronary heart disease characterized by atherosclerosis development in the aortic sinus and coronary arteries, platelet accumulation in coronary artery plaques, myocardial fibrosis, and early death. The gene discussed is SCARB1; the disease is Myocardial fibrosis.