Pre-B-cell colony-enhancing factor, whose expression is up-regulated in activated lymphocytes, is a nicotinamide phosphoribosyltransferase, a cytosolic enzyme involved in NAD biosynthesis. - Rongvaux,A.; Shea,RJ.; Mulks,MH.; Gigot,D.; Urbain,J.; Leo,O.; Andris,F. (Eur J Immunol, 2002)