BCL2 and Parkinson disease: Neuronal apoptosis is another molecular process driven by PD pathology, the damage-associated molecular patterns (DAMPs) upregulate pro-apoptotic factors such as caspase-1, caspase-3, cleaved caspase-3, and Bcl-2 Associated X Protein (BAX), while simultaneously downregulating the anti-apoptotic protein Bcl-2, resulting in the progressive loss of dopaminergic neurons (Koo et al., 2017b).