Moreover, the relationship between LDL-C levels and cognition may be U-shaped as shown in previous research.85 A Mendelian randomization study by Williams et al. did not find support for a preventive effect on AD of lowering LDL-C by pathways related to statins, ezetimibe, or PCSK9 inhibitors.86 In line with our results, this suggests that the rationale for repurposing statins in the cognitive field may be based on mechanisms other than LDL-C lowering. This evidence concerns the gene PCSK9 and Alzheimer disease.