MAPT and Parkinson disease: Mutations in the aforementioned genetic pool contribute to the development of PD and associated neurodegeneration at different cellular-molecular levels: dysfunctions of the membrane compartments, impairment of the mitochondrial system and energetic failure, enzymatic loss-of-function of the autophagy-lysosomal processing and clearance and substrate accumulation, which lead to proteostasis alteration and misfolded aggregates of aSyn (eventually associated with pathological tau protein), inducing metabolic pathway alterations in a bidirectional feedback loop.