PPARGC1A and aortic stenosis: Although these results do not demonstrate a causal relationship between the anti-proteolytic component PGC1α and the atrophic factor FoxO1 in AS-induced HF, they confirm previous reports demonstrating a strong negative correlation between these proteins and provide insights into the functional role of PGC1α in the skeletal muscle in protection against catabolic muscle wasting [14], [71], [75].