Disruption of N-glycan expression in pancreatic adenocarcinoma to reverse the resistance of tumor cells to be killed by chimeric antigen receptor (CAR) T cells was studied by two different approaches, ablation of MGAT5 (mannoside acetyl-glucosaminyltransferase 5) in tumor cells or treating of mice with 2-deoxy-d-glucose. This evidence concerns the gene MGAT5 and pancreatic adenocarcinoma.