APP and Alzheimer disease: Further analysis of the shorter Aβ species Aβ1–41, Aβ1–37 (from Aβ1–43) Aβ1–38 (from Aβ1–42) and Aβ1–34 (from either Aβ1–43 or Aβ1–42) are however needed to better clarify the role of longer Aβ peptides in AD and the pathogenic events linked to Aβ process, degradation and clearance in the presence of APP and PSENs mutations [9–11].