CTLA4 and infection: To extend these observations and provide mechanistic evidence for the role of CTLA‐4 in the control of asymptomatic parasitemia, C57BL/6 mice were infected with P. chabaudi chabaudi, which results in a peak of parasitemia around day 8 post‐infection (p.i) that is resolved after two weeks and followed by asymptomatic recrudescences of low parasitemia (Fig 9H).