Source:http://linkedlifedata.com/resource/umls/id/C0047964
NCI: A yellowish crystalline solid nitrosamine that naturally occurs in tobacco products by oxidation and nitrosation of nicotine during the making and smoking of tobacco. 4-Methylnitrosamino-1,3-pyridyl-1-butanone is only used as a research chemical to induce tumorigenesis. This substance is reasonably anticipated to be a human carcinogen. (NCI05)