Using redox proteomics in a rat heart failure model that causes diaphragm muscle weakness, Kelley et al.67 identified greater cysteine oxidation of thin filament protein including actin, troponin I, and tropomyosin, as well as methionine oxidation of actin and myosin light chains; however a cause-effect relationship between these oxidative modifications and muscle weakness has not been established. This evidence concerns the gene MYH14 and heart failure.