APP and Senile plaques: A peptide of 39–43 mer derived from the amyloid precursor protein (APP), the amyloid β-peptide (Aβ), is the main constituent of senile plaques (SPs) in AD [2], and it is also one of the hallmarks of IBM, a common myopathy characterized by the presence of intracellular amyloid aggregates in skeletal muscle cells [1,3].