NOS2 and cancer: Studies of some tumor types (e.g., colorectal, breast, brain, lung, and cervical cancers) are controversial, indicating either increased or reduced iNOS expression as tumor progresses, whereas in yet other types of cancer (e.g., bladder carcinoma, pancreatic, cervical cancers) positive and even strong iNOS expression was not correlated with either grade/stage or with prognosis.