As ApoE gene knockout mice showed reduced HDL production and attenuated liver cholesterol excretion via the scavenger receptor class B member 1 pathway, an alternative pathway involved the LDLR-LXR-α-ABCG5 pathway, which had been shown to remove cholesterol from the blood and thereby reducing the risk of atherosclerosis in ApoE-/- mice [14, 21]. The gene discussed is APOE; the disease is atherosclerosis.