Notably, several probes that are correlated to the PANAS negative affect score are of special interest: MAFK and SUSD2 are involved in regulation of neurite growth (Kataoka et al., 1995; Nadjar et al., 2015), peripheral blood USP2 expression is correlated to positive psychosis symptoms (Bousman et al., 2010), copy number variants of LTBP1 are associated with alcohol drinking (Pei et al., 2012) and a single-nucleotide polymorphism in the scaffold protein MAGI1 is associated with major depression and neuroticism (Yamagata and Sanes, 2010; Genetics of Personality Consortium et al., 2015). Here, USP2 is linked to major depressive disorder.