MIF and obesity due to melanocortin 4 receptor deficiency: In the present study, obesity significantly suppressed the MIF/AMPK pathway response to exhaustive exercise-induced fatal stress, as indicated by the lower levels of MIF mRNA and protein (Figures 5A-C), pAMPK, and the ratio of pAMPK/AMPK (Figures 5D-F) in the myocardium of mice after exhaustive exercise.