By analyzing the transcriptome data of GSE63060 and GSE63061 peripheral blood cells, we found that pyruvate dehydrogenase (PDHB), succinyl-CoA ligase (SUCLA2) and malate dehydrogenase (MDH1) showed consistent decrease in peripheral blood cells of MCI and AD (Figures 5B, C), which were consistent with the trend in the central system. The gene discussed is PDHB; the disease is Alzheimer disease.