NOS2 and lung carcinoma: CTLS may produce IFN-γ, which in turn may inhibit the immune function of CTLS [83], However, Wu et al. found that silymarin can reduce the level of IL-10 in the immune microenvironment of mice with lung cancer, as well as induce mRNA expression of nitric oxide synthase-2 (iNOS2), MMP9, and alginase -1 (Arg-1), further reducing the proportion of MDSCs and inhibiting their function.