CD244 and activated PI3K-delta syndrome: We found that the frequency of CD160+, CD244+, PD-1+, and CD160+CD244+PD-1+CD8+ T cells is highest in the EBV+ APDS patients (CD160+CD8+: 57 ± 4.9%; CD244+CD8+: 87 ± 3.4%; PD-1+CD8+: 61 ± 8.2%; CD160+CD244+PD-1+CD8+: 36 ± 5.6%), but lower in the EBV− APDS patients and the EBV+ healthy controls (CD160+CD8+: 26 ± 3.8 and 22 ± 4.7%; CD244+CD8+: 43 ± 5.3 and 48 ± 5.9%; PD-1+CD8+: 18 ± 3.0 and 25 ± 7.6%; CD160+CD244+PD-1+CD8+: 5.6 ± 1.5 and 7.0 ± 2.5% for EBV− APDS patients and EBV+ healthy control, respectively).