Treatment with ADI-PEG20 reduces production of inflammatory markers in activated bone marrow-derived macrophages (BMDM). Representative western blots and quantitation of iNOS (A), TNF-α (B), and IL-1β (C), in IFNγ/LPS activated bone marrow derived macrophages (BMDM) treated with 10, 35 or 100 ng/ml of ADI-PEG20 or 100 ng/ml PEG20 as control. n = 3/group, ns = not significant, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 and ∗∗∗∗p < 0.0001.