In the article “Dysregulation of Gene Expression of the 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine-Lesioned Mouse Substantia Nigra,” by Renee M. Miller, Linda M. Callahan, Cindy Casaceli, Linlin Chen, Gretchen L. Kiser, Buena Chui, Tamma M. Kaysser-Kranich, Timothy J. Sendera, Chockalingam Palaniappan, and Howard J. Federoff, which appeared on pages 7445–7454 of the August 25, 2004 issue, the authors inadvertently failed to cite previous reports by Mandel et al. (2000, 2002) and Grunblatt et al. (2001) of microarray studies in MPTP-treated rodents. The missing references are given below. The previous studies used pooled tissues, rather than microdissected substantia nigra used in our studies. Although the approaches are complementary, the use of different starting tissues for the microarray analysis makes comparison difficult.