NR4A2 and synucleinopathy: Fifth, the lithium content in cigarettes may contribute to reduced risk of synucleinopathies by enhancing autophagy of damaged neurons, decreasing the aggregation and phosphorylation of alpha-synuclein, and enhancing β-catenin-mediated activity leading to increased Nurr1 expression through its ability to inhibit glycogen synthase kinase-3 β (GSK-3β) [31].