A study involving 508 CU older individuals and 313 patients with MCI and AD found that CSF levels of five biomarkers of neuroinflammation and cerebrovascular dysfunction (YKL-40, ICAM-1, VCAM-1, IL-15, and Flt-1) were elevated in AD, even during the preclinical and prodromal stages, and were associated with CSF tau. This evidence concerns the gene IL15 and Alzheimer disease.