CD8A and type 2 diabetes mellitus: In addition, the surface expression of the invariant TCR chain Vα7.2 on single CD8+ MAIT cells was increased after two weeks of histidine in the T2D group visits (mean diff = 9.1, SEM = 4.6, p = 0.048), as shown by the mean fluorescence intensity (MFI) of TCR Va7.2 staining (Figure 3(c)).