During clinical malaria, a higher proportion of patients was IgM seropositive and had a higher magnitude of IgM compared to uninfected healthy community controls for merozoites and MSP2 [merozoites: prevalence, 80% versus 26% (P < 0.0001) and magnitude median optical density (OD), 1.17 versus 0.2 (P < 0.0001); MSP2: prevalence, 76% versus 18% (P < 0.0001) and magnitude median OD, 1.24 versus 0.11 (P < 0.0001) Fig. 2, A and B]. Here, CD40LG is linked to malaria.