Two novel NK cell subsets (CD16+CD8+ and CD16+CD8−) were identified in children at high risk of T1DM using dimensional reduction and computational unsupervised clustering approaches; and further analyses revealed that CD16+CD8+ (as CD16+CD8+CXCR3+) and CD16+CD8+CXCR3+CD11c+ NK cells were more abundant in high-risk individuals. Here, CD8A is linked to type 1 diabetes mellitus.