PAK6 and Parkinson disease: We found that LRRK2, MAP2K6, MATK, CDC42EP3, CHGB, PAK6, and SH3GL2 cluster in fewer co-expression modules in brain regions affected in PD (e.g. substantia nigra, caudate and putamen; up to 4 genes in the same module) when compared to the lung tissue (all genes in different modules, Supplementary Table S2), suggesting they are involved in related pathways/functions (e.g. chemical synaptic transmission, Supplementary Table S2) in those brain region but not in the lung.