C4A and schizophrenia: It is noteworthy that another two of the trans-SNPs in IMMS are found in genes that have been associated with this disorder according to another study: rs28919579 is located in the CD4 gene, a locus that has been linked to schizophrenia through an imbalance of CD4 cell subtypes, and rs374886374 is located within the C4A gene, a potential MHC locus that has recently been associated with schizophrenia (Sekar et al., 2016).