Of relevance to substance use disorders, Vrk2 was a human GWAS hit for opioid and cannabis use disorders (Xu et al. 2023), was associated 18 times each with schizophrenia and neuroticism measures, seven times with alcohol consumption or alcohol use disorder (Karlsson Linner et al. 2019; Kranzler et al. 2019; Zhou et al. 2020; Saunders et al. 2022; Kember et al. 2023; Xu et al. 2023), and five times in smoking-related GWAS (Kichaev et al. 2019; Liu et al. 2019; Xu et al. 2020; Saunders et al. 2022; Xu et al. 2023). Here, VRK2 is linked to schizophrenia.