ARG1 and neoplasm: While it has been reported that Arginase 1 can be enhanced in tumors, our data would indicate that given the strong bias in the enrichment of genes associated with T cell activation, the lymphoid compartment over the myeloid compartment and overall antitumor responses observed in the double treated groups, combined with the lack of expression in untreated mice, the enhancement in arginase expression is more likely within activated T cells than tumor-associated macrophages and other suppressive immune cells [71].