Arginase activity ex vivo . Arginase activity was measured by enzymatic assay in PBMCs (A) and bone marrow cells ex vivo (E). The phenotype (B) and percentage (C) of arginase expressing and the MFI of arginase (D) was determined by flow cytometry. Bone marrow cells were isolated from 4 mice and pooled, and PBMCs were isolated from the peripheral blood from 4 mice and pooled. Data show the results of one representative experiment out of four independent experiments. *: p <0.05. Box = interquartile range and median; whiskers = range.