Exploratory Pearson correlations showed that the left AnG GMV was significantly correlated with JOLO scores with no co-variate adjustment in the whole PD cohort (r167 = 0.267; p < 0.001), as well as in PD APOE4 carriers (r49 = 0.323, p = 0.021) and non-carriers (r116 = 0.239, p = 0.009) (S2 Table). Here, APOE is linked to Parkinson disease.