PDCD1 and familial pancreatic carcinoma: CCK receptor inhibition was also demonstrated to enhance the response to immunotherapy in pancreatic cancer: simultaneous blockade of CCK receptors and application of immune checkpoint antibody, PD-1 or CTLA-4, significantly decreased the tumor volume, improved survival of the experimental mice and had an effect on the type and number of immune cells found in the tumor microenvironment [208].