Two significant gene clusters (clusters 7 and 73) included genes previously associated with Parkinsonism (FIG4 and VAC14) [51, 52] and IBD (IFNAR1, IL6ST, ATG16L1, and NOD2) [36] (Fig. 2D and Additional file 1: Fig. S5). This evidence concerns the gene NOD2 and Parkinsonism.