AD patients had elevated urinary CX3CL1 levels compared to CN controls (1.999 ± 1.248 vs. 1.486 ± 1.058 ng/mg creatinine, p = 0.005) and aMCI patients (1.999 ± 1.248 vs. 0.965 ± 0.667 ng/mg creatinine, p < 0.001). This evidence concerns the gene CX3CL1 and Alzheimer disease.