Footnotes

• Contributors Study design and supervision: CML, FZ, KV and LB. Data acquisition and performing of experiments: CML, B-MMS, CG, VD, DAA, PB, L-AG, AK, FL, IC-R, SH, AW, ET, FP, PC, DO, AAn, AAl, MC, XM, JO, FM, TD, S-CL, ES-T, UL, AC, PR, H-PH, OA, PL, MB, TK, CK, UKZ, JTE and BF. Data analysis and interpretation of results: CML, TL, KV and LB. Writing of manuscript: CML and LB with the help of all coauthors.

• Funding This project was funded by grants from the German Ministry for Education and Research (BMBF) and German Research Foundation (DFG; to FZ), the BMBF and the Cure Alzheimer's Fund (to LB), the Walter- and Ilse-Rose-Stiftung (to H-PH and OA), the BMBF (grant NBL3 to UKZ; grant 01UW0808 to UL and ES-T), and the Innovation Fund of the Max Planck Society (M.FE.A.BILD0002 to UL). This project was supported by INSERM, ARSEP, AFM and GIS-IBISA. CML was supported by the Fidelity Biosciences Research Initiative.

• Competing interests LA Gerdes reports to have received travel expenses and personal compensation from Merck Serono, Teva Pharmaceutical Industries, Bayer Schering Pharma, Novartis and Biogen Idec. T Kl reports to have received travel expenses and personal compensations from Bayer Schering Pharmacy, Teva, Merck-Serono, Novartis, Sanofi-Aventis and Biogen-Idec as well as grant support from Bayer-Schering AG. None of the other authors reports any disclosures.

• Provenance and peer review Not commissioned; externally peer reviewed.