NOS1 and neoplasm: 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