NOS2 and neoplasm: The double-positive F4/80 + NOS2 + TAMs were more abundant in both the peritumoral stroma (0.67 ± 0.04 vs 0.98 ± 0.08, P = 0.029) and intratumoral regions (0.46 ± 0.06 vs 0.65 ± 0.02, P = 0.049) of PyMTSB2−/− tumor compared to those of PyMTWT tumors.