CSF2 and pancreatic ductal adenocarcinoma: In a separate vaccine study [106], patients with pancreatic ductal adenocarcinoma (PDAC) received an irradiated, allogeneic pancreatic ductal adenocarcinoma cell vaccine engineered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF), namely GVAX, either alone or combined with low-dose cyclophosphamide to selectively deplete Tregs.