LRRK2 and Parkinson disease: Since NREDs exhibit parkinsonism syndromes and NIID has mitochondrial dysfunction, we thus examined several related protein markers, including LRRK2, one of the most common genetic causes of PD, DRP1, and LC3, that are critical for autophagy and mitochondria function, as well as tyrosine hydroxylase (TH), the rate-limiting enzyme for the conversion of amino acid tyrosine to dopamine [32, 37, 38].