To define the mechanisms underlying the tumor regression phenotype caused by IRE1α loss, we performed RNA-seq of mCherry+ malignant epithelial cells sorted from IRE1αWT or IRE1αKO tumors at two different time points of growth: day 10, when tumor growth was comparable, and day 14, when tumors showed regression induced by IRE1α loss. Here, ERN1 is linked to neoplasm.