Fig. 8.

Arginase 1 is abundant in multiple types of cancer. a Immunohistochemistry of human tumor tissue microarrays stained with an anti-Arg1 antibody were quantified for Arg1-positive infiltrating granulocytes by digital histopathology. b-d Immunohistochemistry staining for Arg1 in sections of normal human tissues (N = 33 tissues analyzed) and human tumor tissues (N = 12 tumor histologies analyzed). Representative images are shown. Red arrows point to arginase-expressing myeloid cells. e Percentage of Arg1-positive cells that co-express the granulocyte marker, CD15, or macrophage marker, CD68, in tumor tissue microarrays as determined by quantitation of MultiOmyx immunofluorescence. f Immunofluorescent staining (MultiOmyx) of a tumor section from a patient with head & neck cancer shows numerous Arg1-positive granulocytes. g Plasma Arg1 protein determined by ELISA from cancer patients (N = 76 from 13 different histologies) and healthy volunteers (N = 31). h Plasma L-arginine determined by LC/MS from cancer patients (N = 26 from 7 different histologies) and healthy volunteers (N = 20). (**** P < 0.0001 vs. healthy donor)