CXCL9 and Alzheimer disease: Positive correlation between median serum concentration of CXCL-11 and CXCL-9 (r = 0.44, P = .03), CXCL-9 and CXCL-10 (r = 0.42, P = .04), and CXCL-10 and IL-18 (r = 0.8, P = .000001) was found in AD patients below 10 years old (Group 1).