CYCS and neoplasm: -Conversion of dietary arginine into nitric oxide. -Increased permeability of mitochondrial membrane and subsequent promoted release of cytochrome c, expression of apoptosis inducing factor, and activation of certain caspases at high level of nitric oxide. -Nitric oxide-induced DNA damage and cell death in cancer cells. -Increased sensitization of resistant tumor cells to apoptosis during chemo-immunotherapy in the presence of nitric oxide.