There is evidence that PACAP can stimulate non-amyloid processing, inhibit Aβ and Tau deposition, promote clearance of Tau and Aβ deposition, improve cognitive ability in AD mice; a lack of PACAP in brain affected the severity of AD pathology in APP/PS1/tau triple-transgenic mice (3xTg mice) [30–34]. This evidence concerns the gene ADCYAP1 and Alzheimer disease.