Among the 27 genes regulated by stroke, 89% were also regulated by PACAP after stroke in an opposite manner, showing that the peptide exerts a strong anti-excitotoxicity, antioxidant, anti-inflammatory, and anti-apoptotic effect as evidenced by its ability to inhibit the expression of genes such as GJB6, NOS-1, IL6, BCL10, and caspase-9 (CASP9) which were induced by stroke. The gene discussed is CASP9; the disease is stroke disorder.