ARG1 and metastatic neoplasm: Data from Figs 6 and 7 suggest that Arg1 but not NOS2 was induced in primary and metastatic tumors and that Arg1 was then negatively affected by the presence of the PLD small-molecule inhibitors, which suggests that the presence of a TAM response could be involved in a non-classical immune response in this human breast cancer formation/metastasis model.