ERN1 and colonic neoplasm: Gao et al. [63] reported that the anticancer drug 5-fluorouracil (5-FU) activates the URP and IRE1α-XBP1 pathway, inducing the expression of ABCB1, ABCC1 and ABCG2 in colon cancer cells, and inhibiting IRE1α RNase can restore drug sensitivity.