NOS2 and neoplasm: To validate the abovementioned observations, we carried out flow cytometric analysis and demonstrated that the populations of tumor-infiltrating monocytes (Ly6C+Cd11b+Cd45+) and M1-like TAMs (iNOS+F4/80+Cd11b+Cd45+) were significantly increased in the TME of B16-F10 tumors from Irg1−/− mice compared with Irg1+/+ controls (Fig. 2E and fig.