IL6 and schizophrenia: In a study comparing 53 patients with schizophrenia and 53 healthy controls intracellular levels of IL-6 mRNA in the peripheral blood mononuclear cells (PBMC) analyzed with quantitative real-time polymerase chain reaction (RT-PCR) was found to be significantly elevated for patients with schizophrenia (55), and PBMC IL-6 mRNA was specifically suggested to be a candidate for a diagnostic marker for schizophrenia (55).