The close relationship between PTSD and systemic inflammation suggests anti- vs.pro-inflammatory cytokine balance may serve as a PTSD resilience biomarker [136].Indeed, PTSD resilience was associated with increased serum levels ofanti-inflammatory IL-4 and IL-10 and decreased proinflammatory IL-12 in Norwegiannavy cadets undergoing a stressful military field exercise [137]. This evidence concerns the gene IL10 and post-traumatic stress disorder.