LDLR and familial hypercholesterolemia: IDOL, the individual E3 ubiquitin ligase, regulates LDLR degradation to induce hypercholesterolemia through the LXR-IDOL-LDLR axis.388,389 IDOL regulates circulating lipid metabolism and the development of atherosclerosis independent of LDLR function.389 A few E3 ligases regulate SREBP.