Depression-like behavior in rodents correlates with increased levels of pro-inflammatory cytokines: interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor α (TNFα) [133,134], and decreased levels of anti-inflammatory interleukin-10 (IL-10) [135]. This evidence concerns the gene IL6 and depressive symptom measurement.