CCL17 and Alzheimer disease: The median serum CXCL-9, CXCL-10, CCL-17, and IL-18 level was statistically significantly lower in AD patients from Group 1 when compared to the Control 1 (56.7 pg/mL versus 87.3 pg/mL; P = .003; 84.8 pg/mL versus 98.0 pg/mL; P = .04; 405.2 pg/mL versus 620.1 pg/mL, P = .04; 64.8 pg/mL versus 94.7 pg/mL, P = .0001; resp).