In this study, we noticed increased numbers of specific CD4+ T cell populations in infected PB and infected SP that had upregulated expression of type I IFN response genes after infection with E. granulosus and high expression of Ifnar1, Ifnar2, and Irf9 in B cell subpopulation B14 (i.e., plasma cells [Sdc1+Ptprc+]) (Fig. S14), indicating that Sdc1+Ptprc+ Breg cells could respond adequately to type I IFN. This evidence concerns the gene IRF9 and infection.