APP and Alzheimer disease: When Breimer and Denny proposed the occurrence of the AD-specific initiation of translation from the AUG codon encoding Met671 of human AβPP [120], such detection was considered impossible because, in a view held at that time, the products of the internal initiation of translation (presumably C99 and, subsequently, Aβ) would be indistinguishable from the corresponding products of the AβPP proteolytic pathway.