ALDH2 and Alzheimer disease: A well-characterized ALDH2 polymorphism, ALDH2*2, that results in reduced or loss of ALDH2 activity, has attracted attention for its association with various diseases including alcohol flushing (Chen C. H. et al., 2022), malignancy (Zhang and Fu, 2021), cardiovascular disease (Chen et al., 2019), and liver disease (Zhang and Fu, 2021; Seike et al., 2022), and evidence that it is also associated with AD has recently been accumulating.