The IL-17 response, while constituting a protective arm defending the body against various infections, also functions as a double-edged sword constituting a risk factor that mediates the development and/or induction of AD, mostly manifested following pathogenic and xenobiotic-induced chronic inflammation; it then acts as a double-edged sword, constituting a risk factor that mediates the development and/or induction of AD, mostly manifested following pathogenic and xenobiotic-induced chronic inflammation. Here, IL17A is linked to Alzheimer disease.