Next, to investigate the potential for infection-induced qualitative shifts in maternal Treg suppressive potency, Foxp3GFP reporter mice on the C57Bl/6 background were substituted for mating with Balb/c males so that maternal Foxp3+ Tregs could be purified as GFP+ CD4 cells by FACS directly ex vivo. This evidence concerns the gene FOXP3 and infection.