APOE and Alzheimer disease: While the observed HDL-C mediated effect of CETP on AD closely follows the aforementioned relationship of Apo-E HDL particles and their role in AD, likely due to the absence of APOE4 stratification and robust AD case ascertainment, the main univariable MR analysis of CETP concentration and AD did not reach similar statistical significance (OR 0.99, 95%CI 0.91; 1.07).