Pathway analysis of all nominally associated genes (p < 0.05) revealed an enrichment of genes involved in Toll-interleukin 1 resistance (SM00255:TIR; p = 7.01 × 10–4), including TLR5, TLR6, TLR8, TLR10, IL1RAP, and IL18RAP, which represent seven unique expression probes that were all upregulated in PTSD cases. The gene discussed is IL18RAP; the disease is post-traumatic stress disorder.