Chronic systemic exposure to lipopolysaccharide from the periodontogenic bacteria Porphyromonas gingivalis increases CatB expression in neurons in middle-aged mice and induces AD-like phenotypes with Aβ accumulation in neurons.45 In this study, EV CatB levels in plasma correlated with those in CSF, and both correlated with CSF Aβ42 and were elevated in the A− to A+ shift. The gene discussed is TYRP1; the disease is Alzheimer disease.