A recent report has shown that IL-1β-expressed inflammatory macrophages produce amyloid β (the main component of the hall marker in the brain of AD patients) in the gingival tissues of the patients with periodontitis as well as in the liver of mice after chronic systemic P. gingivalis infection, indicating that inflammatory macrophages in periodontitis may contribute to neurodegenerative diseases such as AD [34]. The gene discussed is IL1B; the disease is Alzheimer disease.