LDLR and Hypercholesterolemia: Moreover, Seipin and LDLR double knockout (Seipin−/−LDLR−/−) mice even developed extremely hypertriglyceridemia and hypercholesterolemia after high-fat diet (HFD) feeding (Triglyceride: ~6000 mg/dL; Cholesterol: ~8000 mg/dL).