Unbiased clustering revealed four subsets of NK cells in AD, i.e., CD56bright NK cells, CD56dim effector NK cells, adaptive NK cells, and a unique NK cell subset that is expanded and characterized by upregulation of CX3CR1, TBX21, MYOM2, DUSP1, and ZFP36L2, and negatively correlated with cognitive function in AD patients. This evidence concerns the gene CX3CR1 and Alzheimer disease.