XBP1 and infection: To determine if RIDD degrades Tmem173 mRNA, macrophages were pre-treated with the IRE1 endonuclease inhibitor 4μ8c [28] before infection with B. melitensis. As a positive control for 4μ8c efficacy, we assessed inhibition of XBP1 splicing during B. melitensis infection via RT-qPCR (Fig 3D).