Review Question - QID 212314

A 75-year-old man presents to his primary care physician because he has been coughing up bloody sputum over the last week. He also notes that he feels increasingly short of breath and that his coughing has progressively worsened over the last 6 months. His past medical history is significant for hypertension for which he takes lisinopril. Since his last visit about 6 months ago, he has lost 22 pounds (10 kilograms), though he says that he has not changed his diet or exercise patterns. He has a 60-pack-year smoking history and drinks socially. Radiographs are obtained showing a mass in the right lower lobe of the lung and cultures shows no growth on any media. Which of the following intracellular components would most likely be increased in the muscle cells of this patient now when compared to 6 months prior?