IFNB1 and parasitic infectious disease: In our model, mice without CD40 had higher parasitemia on day 4 p. i., died earlier, and had lower levels of IFN-β than the WT mice day 2 p. i. Although there was no correlation between elevated expressions of CD40/STING and IFN-β level at day 5 p. i. in vivo, the down-regulation of IFN-I after day 2 p. i. was likely due to activation of negative regulators in some signaling pathways downstream of STING.