Gut motility and stool moisture showed that chronic rotenone but not vehicle exposure triggered severe constipation in α-SNCA mice; in contrast, these effects were abolished in α-SNCA/AEP−/− and α-SNCA/C/EBPβ+/− mice, indicating that C/EBPβ/AEP somehow mediates these prodromal effects in PD (Fig. 5a). This evidence concerns the gene CEBPB and Parkinson disease.