NOS2 and neoplasm: The co-culture with TC-1 cells significantly increased iNOS activity in both types of TAMs that were stimulated with the combination of IFN-γ and ODN1826 (Figure 4A,B; left-hand graph), while arginase activity was markedly enhanced in IL-4-activated TAMs by co-cultivation with these tumor cells (Figure 4A; right-hand graph).