CD40 and parasitic infectious disease: Compared with WT mice, both infected male (n = 9) and female (n = 3) CD40-/- mice had significantly higher day 4 parasitemia (P = 0.0078 for male; P = 0.0137 for female) (Fig 1A and 1B) and died earlier (Ave survival days, WT over 25 days vs KO 15 days for male, P<0.001; 15 days vs 10 days for female, P = 0.0623) than the WT mice (Fig 1C).