PDCD1 and pancreatic neoplasm: In an orthotopically transplanted mouse model using pancreatic cancer cells isolated from tumors of transgenic KrasLSL-G12D/+, Trp53LSL-R172H/+, Pdx1-Cre (KPC) mice that express PD-L1, tumors were sensitized to anti-PD-1/PD-L1 therapy in response to cabozantinib-depleted PMN-MDSCs.