TNF and obesity due to melanocortin 4 receptor deficiency: What is clear however, is that one link is likely to be through increased TNF-α levels in both obesity and insulin resistance (Hotamisligil et al. 1995) which has an apoptotic effect on skeletal muscle tissue (Kewalramani et al. 2010) and would in that manner, negatively impact on the function of the muscle-tendon unit as a whole.