In T1DM, a statistically significant negative correlation was detected between CD4+CD28null T-cell frequency and Tregs (R = −0.28; P = 0.015), likely suggesting the preferential association of increased CD4+CD28null T-cell immune response with impaired Treg function in single T1DM patients (Figure 2(a)). The gene discussed is CD4; the disease is type 1 diabetes mellitus.