During animal development, homeostasis, and aging, anything that grows eventually decays or undergoes consumption, which is known as atrophy or wasting. Thus, like growth, wasting is a fundamental biological process. Importantly, wasting is also part of a complex systemic disorder associated with many diseases. Cachexia, the wasting syndrome commonly observed in advanced cancer patients, affects approximately eight million people worldwide. Due to the complexity of the disease, it is challenging to dissect the molecular mechanisms of cachexia.