The refractory response of pancreatic ductal adenocarcinoma(PDAC) to multiple treatment regimens can be attributed to the presence of a desmoplastic stroma together with an immunosuppressive tumor microenvironment.In a recent study published in Cell,Koikawa et al.demonstrate that targeting the proline isomerase,Pin1,potentiates the efficacy of immunochemotherapy and enhances the susceptibility of highly resistant PDAC to the anti-tumor immune response.