For CD4+ T cells, the percentages of PD-1+ and CD244+ expression were elevated in children with Down syndrome (mean 25.9 ± 2.0 and 7.6 ± 1.0, respectively), compared to controls (mean 12.9 ± 1.9 and 4.6 ± 0.9). The gene discussed is CD4; the disease is Down syndrome.