Based on the Child–Pugh classification, serum irisin concentrations in the no sarcopenia group were 264.15 pg/ml (IQR: 157.49, 358.95) for Child–Pugh A, 320.00 pg/ml (IQR: 210.39, 373.09) for Child–Pugh B, and 244.54 pg/ml (IQR: 143.18, 386.45) for Child–Pugh C. In the sarcopenia group, serum irisin concentrations were 149.41 pg/ml (IQR: 77.93, 189.65) for Child–Pugh A, 40.63 pg/ml (IQR: 18.84, 151.65) for Child–Pugh B, and 23.71 pg/ml (IQR: 16.48, 33.92) for Child–Pugh C (Table 3). The gene discussed is FNDC5; the disease is sarcopenia.