PPARGC1A and interstitial lung disease: Patients with sarcopenia have been found to have reduced PGC‐1α in their skeletal muscle but enhanced interleukin‐6 and tumor necrosis factor‐α expression, causing inflammation and muscle proteolysis36, 37 Previous studies have suggested that inflammation and undernutrition may contribute to the prognosis and exacerbation of ILD.14, 38, 39, 40, 41