ERN1 and parasitic infectious disease: To address whether Toxoplasma targets IRE1 in immune cells to enhance their migration and facilitate dissemination, we infected bone marrow-derived dendritic cells (DCs) with Toxoplasma. Levels of XBP1s mRNA were sharply increased upon Toxoplasma infection in DCs (Fig. 4A), consistent with the idea that the parasite infection activated IRE1 in this cell type.