At day 20 post-infection mice, once PbNK65 hrfΔ parasite was eliminated and memory B cells were generated, splenic B cell populations were analysed by flow cytometry using a combination of cell surface markers according to a gating strategy on CD19+ AID-YFP+ cells followed by gating on GL7+ CD95+ cell population and finally gating on IgG+ or IgM+ cell populations (Supplementary Fig. 6). The gene discussed is FAS; the disease is infection.