BACE1 and Alzheimer disease: To investigate the distribution of early endosomes and lysosomes in the AD flies, Drosophila brain sections for control w1118, AβPP, Aβ1–42 × 2 and AβPP‐BACE1 flies were stained with a Drosophila anti‐rab5 antibody, investigating the presence of early endosomes (Fig. 2A), or with a Drosophila anti‐LAMP1 antibody, investigating the presence of lysosomes (Fig. 2B).