This, in turn, explains the decreased β7 integrin expression and IFN-γ production by MAIT cells from children with type 1 diabetes (Fig. 3), as they demonstrate an inverse correlation with the frequency of CD8−CD27− MAIT cells and their expression is markedly lower on DN CD27− MAIT cells compared with CD8+CD27+ MAIT cells. Here, CD27 is linked to type 1 diabetes mellitus.