IL6 and post-traumatic stress disorder: Other studies have shown that in individuals with PTSD, the levels of pro-inflammatory cytokines, such as IL-6 (Maes et al., 1999[50]), IL-1β (Jones et al., 2015[31]), or IL-2 (Smith et al., 2011[82]) are augmented, and these levels are positively correlated with PTSD symptoms in traumatized individuals (von Känel et al., 2007[98]).