CTLA4 and neoplasm: When added to CTLA-4 mAb, PD-L1 mAb did not enhance the rate of tumor rejection over that observed with CTLA-4 mAb alone (50% vs. 45%, respectively), suggesting that the enhanced MOC1 tumor elimination observed with gMDSC depletion and CTLA-4 mAb was not fully attributable to elimination of PD-L1 expressed on gMDSC.