IL6 and post-traumatic stress disorder: Thus, the specific objective of this work was to create and validate a diagnostic algorithm for combat-related PTSD that integrates clinical data with a panel of serum biomarkers, including markers of BBB integrity (antibody levels to glial fibrillary acidic protein (GFAP) and neuron-specific enolase (NSE)), HPA axis dysfunction (cortisol), and neuroinflammation (levels of interleukin-6 (IL-6) and interleukin-8 (IL-8)).