ACAT enzymes are crucial components of cholesterol metabolism, and inhibition of their activity has great therapeutic potential, e.g., against hyperlipidemia, atherosclerosis, Alzheimer ́s disease, Niemann Pick C disease, viral activity, and tumor growth (Giovannoni et al., 2003; Llaverias et al., 2003; Hutter-Paier et al., 2004; Huttunen et al., 2007; Yue et al., 2014; Yang et al., 2016; Bandyopadhyay et al., 2017; Li et al., 2018; Chang et al., 2021; Ren et al., 2021; Rogers et al., 2022; Wing et al., 2023). Here, ACAT1 is linked to early-onset autosomal dominant Alzheimer disease.