CD4 and asthma: Although the numbers of sialyl LeX positive FOX3+ CD25+ Treg cells among CD4+ cells did not reach statistical significance between children with mild-to-intermittent asthma and healthy controls, children with moderate-to-severe asthma had a lower proportion of both the total cells and the CCR7+ subset of sialyl LeX positive FOX3+ CD25+ Treg cells, among CD4+ T cells (Fig. 5c).