Correction: In Figure 1 of the article “Accelerated Accumulation of Misfolded Prion Protein and Spongiform Degeneration in a Drosophila Model of Gerstmann–Straussler–Scheinker Syndrome,” by Brendan A. Gavin, Maria J. Dolph, Nathan R. Deleault, James C. Geoghegan, Vikram Khurana, Mel B. Feany, Patrick J. Dolph, and Surachai Supattapone, which appeared on pages 12408–12414 of the November 29, 2006 issue, the anti-PrP monoclonal antibody D13 (InPro Biotechnology, South San Francisco, CA) was used to compare PrP expression levels between different transgenic Drosophila lines. In retrospect, the authors have realized that the D13 epitope encompasses residue 101 and that consequently, this antibody has poor affinity for P101L PrP. As a result, the Western Blot shown in Figure 1 does not accurately reflect the relative PrP expression levels between the PRNP/GAL4-Cha2 and GAL4-Cha2;P101LD lines assayed. Using two alternative anti-PrP antibodies, whose epitopes do not include residue 101, the authors have found that GAL4-Cha2;P101LDflies actually express >20-fold more PrP than PRNP/GAL4-Cha2 flies. Thus, with the transgenic lines currently available, the authors cannot exclude the possibility that expression ofWTPrP at higher levels might also cause spongiform degeneration in Drosophila.