We observed that expression of inflammation- and immune cell-related genes LCN2, PTPRC, and CD8B was significantly increased in colon tissue from a small cohort of PD patients compared to matched HCs, as was expression of SNCA, which encodes a key protein associated with PD pathology and which is upregulated in the intestine under inflammatory conditions [56]. This evidence concerns the gene CD8B and Parkinson disease.