ERN1 and neoplasm: UPR activation endows malignant cells with greater tumorigenic, metastatic, and drug resistant capacity.17 XBP1 is overexpressed in colon cancer cells, whereas it was found to be unreactive in normal colon epithelial cells.34 In tumor microenvironment, nutrient deprivation, oxygen limitation, high metabolic demand, and oxidative stress, disturb the protein-folding capacity of the ER, thereby provoking a cellular state of ER stress.17,35,36 The IRE1α-XBP1 pathway may reasonably be considered a target candidate for cancer treatment.