PHARMACOLOGY. For the article “Beneficial effects of antioxidants and l-arginine on oxidation-sensitive gene expression and endothelial NO synthase activity at sites of disturbed shear stress,” by Filomena de Nigris, Lilach O. Lerman, Sharon Williams Ignarro, Giacomo Sica, Amir Lerman, Wulf Palinski, Louis J. Ignarro, and Claudio Napoli, which appeared in issue 3, February 4, 2003, of Proc. Natl. Acad. Sci. USA (100, 1420–1425; first published January 13, 2003; 10.1073/pnas.0237367100), the authors should have noted that Louis J. Ignarro developed and markets Niteworks, a dietary supplement of l-arginine, l-citrulline, vitamin E, and vitamin C. Dr. Ignarro is also a member of the Scientific Advisory Board of Herbalife, the distributor of Niteworks.