Previous studies have suggested that a frequently occurring single-nucleotide polymorphism (SNP) of the KIBRA gene (rs17070145), may be implicated in cognitive performance, especially memory performance, and may constitute a modest risk gene for AD and other dementias such as vascular dementia, but also SUD (Bauer et al., 2012; Kawai et al., 2015; Mazzeo et al., 2019; Wang et al., 2021). The gene discussed is WWC1; the disease is Alzheimer disease.