Third, although the upregulation of ATF4 triggered by ER stress in patients with NAFLD may contribute to the age-related progressive loss in the muscle mass and strength through the upregulation of LECT2, additional research is needed to elucidate the role of ATF4 and the specific mechanisms by which LECT2 influences sarcopenia. The gene discussed is ATF4; the disease is metabolic dysfunction-associated steatotic liver disease.