LRBA deficiency and CTLA-4 deficiency have different patterns of expression. (A) Representative expression of Foxp3 and total CTLA-4 (BN13) on unstimulated (Unstim) and stimulated (Stim) memory CD4 T cells from control or LRBA mutations. CD4 T cells were stimulated with CD3/CD28 beads; CTLA-4 MFI is shown in large font. (B) Relative expression of CTLA-4 in healthy controls and LRBA-deficient patients (n = 5) in unstimulated or stimulated conditions. Relative expression is calculated as the fold change in CTLA-4 MFI between nTcon and mTreg. (C) Fold increase in CTLA-4 MFI between Foxp3⁺ memory CD4 T cells before and after stimulation with CD3/CD28 beads. (D) Foxp3⁺ Treg percentage in unstimulated or stimulated LRBA-deficient and control CD4 T cells. (E) CD4 T cells were stimulated with CD3/CD28 beads in the presence of absence of BafA and stained for Foxp3 and total CTLA-4 (BN13) expression. CTLA-4 MFI in Foxp3⁺ mTregs is shown in large font. (F) Collated BafA data for healthy controls, CTLA-4, or LRBA mutations. Fold increase is the change in CTLA-4 MFI in mTregs before and after BafA treatment.