CTLA4 and malaria: Following the increase in the absolute numbers of Treg subpopulations, P. vivax infected donors presented a significant higher expression level of all markers tested (CTLA-4, GITR, TGF-β, IL-10, IFN-γ and IL-17) on CD4+CD25+FoxP3+ cells when compared to those observed on malaria-naïve subjects (P<0.0001 for all, Figure 3).