FOXP3 and incontinentia pigmenti: In addition, a reduced number of CD4+ CD25+ FOXP3+ Tregs was observed in the CTD-IP patients compared with normal controls (7.32 ± 2.21 % in CTD-IP vs. 8.36 ± 1.81 % in control, P = 0.035), as shown in Fig. 2e.