Mechanistically, differentiated C2C12 myotubes were treated with recombinant GDF11 (rGDF11), followed by assessment of canonical SMAD signaling and muscle atrophy-related markers, including phosphorylated SMAD3 (immunoblotting) and the E3 ubiquitin ligases Atrogin-1 and MuRF1 at both protein (immunoblotting) and transcript (RT-qPCR) levels.<h4>Results</h4>Circulating GDF11 concentrations were significantly higher in older adults than in younger individuals and were further elevated in participants with sarcopenia, both before and after PSM. The gene discussed is FBXO32; the disease is sarcopenia.