Pancreatic cancer has one of the lowest response rates to immunotherapy, recently demonstrated in a clinical trial, where 3.1% of patients with metastatic PDAC responded to dual immunotherapy with durvalumab (PD-L1 blocking antibody) and tremelimumab (CTLA-4 blocking antibody), and 0% to durvalumab monotherapy (61). Here, CTLA4 is linked to familial pancreatic carcinoma.