There are errors in the "Gene chip hybridization" paragraph in Materials and Methods. The correct text is: "Total RNA was isolated using TRIzol Reagent (Invitrogen, Carlsbad, CA, USA.) followed by a cleanup step with qiagen RNeasy mini columns (Qiagen, Cologne, Germany) and quality-controlled by 2100 Bioanalyzer (Agilent, Santa Clara, CA, USA). The expression profile of rat tissues and cells was analysed using rat 230A-arrays from Affymetrix (Santa Clara, CA, USA) according to the Genechip expression analysis technical manual 701025 Rev.2. Briefly, 5 μg RNA was used to synthesize double-stranded cDNA with the Superscript Choice system (Invitrogen Corporation, Carlsbad, CA, USA ) using an oligo(dT) primer containing a T7 RNA polymerase promoter (Affymetrix,GenSet, Paris, France) and cDNA was in vitro transcribed to synthesize biotin-labeled antisense cRNA (BioArray high yield RNA transcript labelling kit; Enzo Diagnostics, Farmingdale, NY, USA). After fragmentation at 94°C for 35 min in 40 mM Tris, 30 mM magnesium acetate, 10 mM potassium acetate, labeled cRNA was hybridized for 16 h on Affymetrix (Santa Clara, CA, USA) expression arrays. Arrays were washed and stained with phycoerythrin-streptavidin (SAPE) in Affymetrix Fluidics Station 400 and scanned by Affymetrix 3000 GeneScanner."