NOS are composed of subtypes according to naming, constitutive and inducing roles; neuronal NOS (nNOS)and endothelial NOS (eNOS) are responsible for neurotransmission and vasodilatation while inducible NOS (iNOS) conducts macrophages and tumor-induced immunsupression.12,13 NOS is expressed by several tumors like human ovarian, stomach and breast carcinoma.14 There are reports defining selective expression of iNOS in human prostate carcinoma in the literature.15,16. This evidence concerns the gene NOS3 and neoplasm.