ABCG2 and malignant colon neoplasm: Although IRE1α’s relationship to ABC transporters has not been clearly established in HCC, Gao et al. (2020) found that the IRE1α–XBP1 axis participates in activating efflux pumps ABCC1 and ABCG2 in colon cancer cells resistant to 5-fluorouracil [44].