At the cellular level, SNP CT60 is correlated with changes in mRNA levels of sCTLA-4; lower levels of sCTLA-4 mRNA were detected in resting CD4+ T cells and CD4+ CD25+ FOXP3+ Tregs of healthy donors carrying a T1D-susceptible genotype at SNP CT60 as compared with donors having the protective genotype (10, 17). Here, CD4 is linked to type 1 diabetes mellitus.