UCHL1 and Parkinson disease: Given that UCHL1 has been reported to be a susceptibility gene for PD and proposed as a potential target for therapy [52], whose downregulation contributes to protein aggregation in Lewy bodies [53] – a hallmark of PD pathology, it is possible that the upregulation of UCHL1 due to smoking protects against UCHL1 loss-of-function that predisposes the cells to PD related symptoms.