Background Pancreatic Ductal Adenocarcinoma (PDAC) is a malignancy with a highly immunosuppressive tumor microenvironment (TME), showing strong resistance to immune checkpoint blockade (ICB) therapies, such as anti-PD-1 and anti-CTLA-4 treatments. Myeloid-Derived Suppressor Cells (MDSCs) derived from tumors play a critical role in tumor immune supp...