Although some studies did not find significant statistical differences in IL -6 levels between the PTSD group and HC, important elements identified included an upward trend in IL6 [24], the isolated loss of the biphasic plasma peripheral IL-6 circadian pattern with attenuated plasma circadian variability in PTSD compared with HC [23], a positive correlation with symptom severity [34] and higher IL-6 salivary levels as a signal of anticipatory anxiety in the whole sample. The gene discussed is IL6; the disease is post-traumatic stress disorder.