MMP9 and neoplasm: Since matrix metalloproteinase 9 (MMP9) expression in the PDAC tumor microenvironment has multiple protumorigenic effects [61], and an anti-MMP9 antibody has antitumor activity in combination with nab-paclitaxel-based chemotherapy in preclinical PDAC models [62], the MMP9 antibody andecaliximab (GS-5745) was evaluated in combination with nabP/Gem in patients with advanced PDAC in a phase I study.