Alternative cleavage and polyadenylation (APA) have gained increasing attention in cancer biology, yet its role in modulating anti-tumor immune response remains largely unexplored. Here, we identify the cleavage stimulation factor 2 (CSTF2), an APA-related gene, as a pivotal suppressor of anti-tumor immunity in pancreatic ductal adenocarcinoma (PDAC). CSTF2 promotes tumor development by inhibiting the infiltration and cytotoxic immune cell recruitment function of TCRαβ