CD4 and abortion: To determine whether tregitopes administration to abortion-prone mice after mating could stimulate Tregs expansion, the percentage of CD4+CD25+FOXP3+ and CD4+CD25+FOXP3+IL-10+ cells in the spleens and uterine-draining lymph nodes (Fig. 3) of the animals were analysed based on the gating strategy shown in Fig. 2.