Numerous investigations support upregulated inflammatory activity in PTSD (for review see Gill et al. 2009), including increased production of IL-6 (Maes et al. 1999; Bob et al. 2010), increased TNF-α, IFN-γ, IL-1β, and decreased production of interleukin-8 (IL-8) and interleukin-2 (IL-2). Here, CXCL8 is linked to post-traumatic stress disorder.