Additionally, a significantly lower number of PanIN-1 lesions and absence of any carcinoma in NKPC mice as compared to the KPC mice, of which 30 percent (2 out of 6) showed the presence of carcinoma at an early age of 6 week, indicated an increased tumor-latency in NOS2-deficient NKPC mice. This evidence concerns the gene NOS2 and neoplasm.