NR4A2 and Parkinson disease: Out of the three lithium dosages tested in this small pilot trial, medium-dose lithium aspartate therapy was associated with the largest numerical increases in expression of blood-based PD therapeutic targets Nurr1 and SOD1 and the most uniform improvements in the MRI-based disease-progression biomarker FW in sites previously shown to reflect progressive motor and cognitive decline in PD (Ofori et al., 2015; Burciu et al., 2017; Guttuso et al., 2022).