In preclinical models of colon cancer, PERK-inhibition made ER stress-resistant/MDR tumors as responsive to oxaliplatin as ER stress-sensitive/chemosensitive tumors: this chemosensitizing effects was likely due to the decreased expression of MRP1 that restored the pro-apoptotic effects of oxaliplatin in resistant tumors. This evidence concerns the gene EIF2AK3 and colonic neoplasm.