CD274 and neoplasm: Hyaluronan has been shown to contribute to tumor promotion and depletion by PEGylated recombinant human hyaluronidase PH20 (PEGPH20) 24 h prior to anti-PD-1 or anti-PD-L1 therapy significantly suppressed tumor growth, when compared to either modality alone, in high hyaluronan-expressing pancreatic tumor mice models [27].