CD34 and pancreatic adenocarcinoma: Finally, the potential of the different CEA-4-1BBL antibody fusion proteins as signal 2 providers in combination with CEA-TCB was tested in vivo in human CD34+ stem cell humanized NSG mice bearing subcutaneous human gastric adenocarcinoma MKN-45 or human pancreatic adenocarcinoma HPAFII xenografts.