iNOS overexpression in prostate cancer cells and thyroid cancer demonstrates an anticancer effect due to cell death induction [101] and the inhibition of tumorigenesis [102], while in gastric cancers, hepatocellular carcinoma, melanoma, leukemia, and osteosarcoma, iNOS expression correlates with tumor progression and with the degree of malignancy [103]. This evidence concerns the gene NOS2 and prostate cancer.