IL6 and Parkinson disease: The expression levels of pro-inflammatory factors and proteases, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and interferon-gamma (IFN-γ) and metalloproteinase-3 (MMP-3), which are canonical SASP factors, are elevated in the brains of patients with Parkinson’s disease (19).