Utilizing CD45RA and CCR7 as markers to distinguish antigen-experienced (CD45RA-) versus naïve T cells (CD45RA+CCR7+), healthy subjects tended to have a higher proportion of GK-reactive T cells that were naïve than subjects with T1D (p = 0.06) (Fig. 3b). Here, CCR7 is linked to type 1 diabetes mellitus.