TNFSF12 and chronic obstructive pulmonary disease: By contrast, mRNA levels of TWEAK and Fn14 remained unaffected in skeletal muscle of mice in response to high doses of glucocorticoids (43) and in skeletal muscle of patients with chronic obstructive pulmonary disease (70) indicating that TWEAK/Fn14 system may not be the mediator of muscle atrophy in all conditions.