FOXP3 and asthma: Second, epigenetic reprogramming, based on epigenome-wide association studies (EWAS), shows that the promoter region of the FOXP3 gene, which regulates the differentiation of regulatory T cells (Treg), is hypermethylated in the umbilical cord blood DNA of HDP-exposed offspring, which may promote asthma by enhancing Th2 immune polarization (32, 33).