MFN2 and sarcopenia: For example, the ablation of OPA1 mitochondrial dynamin like GTPase induced FOXO signaling and unfolded protein response which caused catabolic program of muscle loss and systemic aging[148] and mice without mitochondrial pro-fusion factors such as Mfn2 (mitofusin 2) in skeletal muscle developed significant defects of muscle growth and sarcopenia[149].