CD4 and allergic disease: With respect to T cells, we observed that the proportion of infant cord blood CD4+ T cells that expressed the marker of naivety CD45RA or that had the FOXP3+CD25high phenotype, regarded as a marker of regulatory T cells, were positively associated with allergy, in the PCA as well as in the OPLS, although the differences between these variables did not reach statistical significance in the univariate analysis.