Despite the fact that UCH-L1 is prevalently soluble in the cytosolic compartment (UCH-L1S), around 20–50% could be membrane-associated (UCH-L1M) [13,16], and the latter has been associated with aberrant α-synuclein accumulation in Parkinson’s disease (PD) [17]. This evidence concerns the gene UCHL1 and Parkinson disease.