A recent genome-wide association study (GWAS) also demonstrated the relationship between MPP6 and various psychiatric disorders: the MPP6 gene was included in 64 genome loci for bipolar disorders compared among European ancestry [131], in 109 genome loci associated with at least two psychiatric disorders including anorexia nervosa, attention-deficit/hyperactivity disorder, major depression, obsessive–compulsive disorder, schizophrenia, and Tourette syndrome [132], and in 108 genome loci for schizophrenia patients [133]. Here, PALS2 is linked to major depressive disorder.