Fourth, analyzing inflammatory mediators like cytokines (e.g., IL-1β, IL-6, TNF-α), chemokines (e.g., fractalkine), and AD biomarkers (e.g., Aβ40, Aβ42) in the synovial fluid from the affected joints in OA patients would reflect the local environment within the OA joint. Here, IL6 is linked to Alzheimer disease.