Representative Ponceau S-stained membrane was used to control for equal protein loading and transfer differences. Membrane was scanned, and lanes were quantified to normalize Western blots to protein loading. Lane 1, sedentary control (Sed); lane 2, exercise-trained, no treatment (ExTr); lane 3, sedentary, doxorubicin-treated (SedDox); lane 4, exercise-trained, doxorubicin-treated (ExTrDox). MW, molecular weight.