S100A9 and neoplasm: Protumor neutrophils, on the other hand, are immunosuppressive and foster tumor invasion, metastasis, and angiogenesis by releasing NE and other proteins, e.g. matrix metalloproteinase-9 (MMP-9), S100 calcium-binding protein A8 (S100A8), S100 calcium-binding protein A9 (S100A9), Bv8, and high mobility group box 1 (HMGB1) (73, 78, 79, 169, 170).