In subsequent experiments, we found that the expression levels of endoplasmic reticulum stress pathway-related proteins, such as α-synuclein, GRP78, p-IRE1α, ASK1, p-JNK, and caspase-12, were increased in the rat midbrain of the model group, suggesting the presence of ERS in PD animals. This evidence concerns the gene MAP3K5 and Parkinson disease.