A recent imaging genetics study of a mixed sample of healthy control subjects (n = 46), patients with psychosis (n = 40) and individuals at clinical high risk for psychosis (n = 43) showed that levels of genotype-predicted brain C4A expression were positively associated with brain levels of translocator protein (TSPO, a marker expressed by glia), and negatively associated with hippocampal surface area [84]. This evidence concerns the gene TSPO and psychotic disorder.