Pyroglutamate amyloid beta3–42 (pGlu-Abeta3–42), a highlyamyloidogenic and neurotoxic form of Abeta, is N-terminally truncated to form apyroglutamate and has recently been proposed as a key target for immunotherapy.Optimized ACI-24, a vaccine in development for the treatment and prevention ofAlzheimer’s disease, focuses the antibody response on the first 15N-terminal amino acids of Abeta (Abeta1–15). This evidence concerns the gene APP and glycogen storage disease VI.