Through the results of the pathway terms relationship network, it can be inferred that the genes related to oxidative phosphorylation and the genes in class I mhc-mediated antigen processing presentation play critical roles in MDD, which all overlap with related genes of neurological diseases (Alzheimer’s disease, Parkinson’s disease, and Huntington disease) (12). This evidence concerns the gene HLA-C and early-onset autosomal dominant Alzheimer disease.