Besides, TNF-α, a pro-inflammatory protein, could increase the process of apoptosis via intrinsic and extrinsic pathways, which is more significantly visible in aged brain and could be implicated in neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD) (Figure 4) (199–201). The gene discussed is TNF; the disease is Parkinson disease.