However, one of the most fundamental levels of immune-CNS interaction emerges from the Human Leukocyte Antigen (HLA) locus (Major Histocompatibility Complex (MHC) in mice; HLA and MHC are used interchangeably); genome-wide association studies (GWAS) show that the HLA locus is one of the most significant determinants of schizophrenia susceptibility [20–22]. This evidence concerns the gene HLA-C and schizophrenia.