The non-motor symptoms such as gut permeability and constipation were frequent in the PD patients (Felice et al., 2016), therefore, we also explored the genes involved in the tight junctions and gut barrier functions and found that the epithelial cell adhesion molecule (Epcam or CD326) was upregulated in SNCA-TG genotype compared with WT in the standard environment. Here, EPCAM is linked to Parkinson disease.