Humanin(HN)is a 24-aa peptide encoded by a newly identified gene cloned from an apparently normal brain region from patients with Alzhermer s disease(AD)in 2001.Studies showed that HN protected neurons from insults of various familial Alzheimer s disease mutations(APP、PS-1 and PS-2),anti-APP(amyloid precussor protein,APP)antibodies, amyloid peptide(Aβ)(Aβ1-43 or Aβ1-42)and its segments(Aβ25-35、Aβ31-35)with efficiency.It seemed that HN didn t inhibit other toxic insults to neurons,such as Fas,etoposide, glut...