However, more recent large-scale genome-wide association studies evaluating very large sample collections for hundreds of thousands of single-nucleotide polymorphisms (SNPs) have shown variants significantly associated with higher risk of schizophrenia at CSMD1 (Schizophrenia Psychiatric Genome-Wide Association Study (GWAS) Consortium, 2011) and C4 genes (Sekar et al., 2016). This evidence concerns the gene C4A and schizophrenia.