No correlation was observed between Treg and iTreg (Supplementary Figure S7a), between Treg and nTreg (Supplementary Figure S7b) or between the FOXP3 MFI and iTreg (Supplementary Figure S7c) and the FOXP3 MFI and nTreg (Supplementary Figure S7d), regardless of newborns’ sex or maternal allergy status. Here, FOXP3 is linked to allergic disease.