On the other hand, a cohort study in the United Kingdom showed that incretin-based therapies, including dipeptidyl peptidase-4 (DPP-4) inhibitor and glucagon-like peptide 1 receptor (GLP-1R) agonists, were associated with an increased risk of CCA in adults with type 2 DM21. Here, DPP4 is linked to cholangiocarcinoma.