Treadmill exercise tolerance test. After acclimatization, mice were run on a treadmill with a 10% slope and increasing speed to exhaustion. Maximum speed and running time were monitored, and distance, work, and power were calculated based on the individual performance. (A) Running time; (B) Speed; (C) Distance; (D) Work; and (E) Power. Data are represented as mean ± SD. N = 6 in each group. *P <0.05; values vary significantly between wild-type and TWEAK-KO mice. KO, knockout.