To determine whether P-IRE1α is involved in macrophage death caused by the ΔrfbE mutant, the inhibitor of IRE1α, 4μ8c, was used to treat the macrophages before infection, which blocks the access of the substrate to the active site of IRE1α, and selectively inactivates both Xbp1 splicing and IRE1α-mediated mRNA degradation (Cross et al., 2012). The gene discussed is XBP1; the disease is infection.