JNeurosci is publishing an Expression of Concern for the article, “Plasticity of Subventricular Zone Neuroprogenitors in MPTP (1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine) Mouse Model of Parkinson’s Disease Involves Cross Talk between Inflammatory and Wnt/β-Catenin Signaling Pathways: Functional Consequences for Neuroprotection and Repair,” by Francesca L’Episcopo, Cataldo Tirolo, Nunzio Testa, Salvatore Caniglia, Maria C. Morale, Michela Deleidi, Maria F. Serapide, Stefano Pluchino, and Bianca Marchetti, which appeared on pages 2062–2085 in the February 8, 2012 issue. The editors have been made aware of image duplication concerns in Figures 1B, 9H, 5J, and 6D. Per journal policy, the authors were contacted to provide an explanation and/or original data for the editors to review and determine if corrective actions were required. Due to the age of the article, the authors have experienced difficulties in responding to the concerns. Until more information can be provided and independently evaluated, the Editorial Board cautions readers that the results reported within the article may not be reliable.