MT-RNR2 and early-onset autosomal dominant Alzheimer disease: Formyl peptide receptor 2 (FPR2) has been shown to mediate the cytotoxic effects of the β amyloid peptide Aβ42 and serves as a receptor for humanin, a peptide that protects neuronal cells from damage by Aβ42, implying its involvement in the pathogenesis of Alzheimer’s disease (AD).