MPO and neoplasm: A number of granule genes typically expressed by mature neutrophils, in particular, the primary granule proteases neutrophil elastase (Elane), proteinase 3 (Prtn3), cathepsin G (Ctsg) and myeloperoxidase (Mpo)17 (Fig. 4i,j), and genes expressed in mature, fully differentiated granulocytes, such as S100a8 and Camp17 (Fig. 4i and Supplementary Table 1) were highly expressed in PMN-MDSC from tumor-bearing Shp2f/fLysMCre compared to Shp2f/f mice.