The findings also revealed that the protein expression levels of eight AED-metabolizing enzymes (GSTP1, GSTO1, CYP2E1, ALDH1A1, ALDH6A1, ALDH7A1, ALDH9A1 and ADH5) are significantly upregulated at the BBB in the focal site of epilepsy patients, whereas the protein expression levels of tight junction molecules are significantly downregulated and this is accompanied by an increased infiltration of blood proteins. The gene discussed is ALDH6A1; the disease is epilepsy.