Further we omitted the depressed control subjects (44.01 / 35.94–67.43 pg/ml) and compared CSF IL-8 levels with these of AD patients (35.90 / 29.67–46.16 pg/ml) and observed the same difference as when the depressed control subjects were included (p = 0.03) (Additional file 1: Figure S1C). The gene discussed is CXCL8; the disease is Alzheimer disease.