Although the shared DEGs do not converge on a single pathway, they comprise multiple cellular functions aligning with known PD-related processes including oxidative stress response and proteostasis (Ephx2, Rtn4ip1, Retsat, Pex11a, Ube3d) or immune signalling (Ilr3a, Selplg, Mpeg1, Tmem119), the latter being consistent with an activated inflammatory environment in the gut of BAC SNCA rats [32]. This evidence concerns the gene SELPLG and Parkinson disease.