TRIM63 and Atrophy: Three key mRNAs in muscle loss are muscle RING finger-1 (MuRF1, also called Trim63), muscle atrophy F-box (MAFbx, also called Fbxo32 and Atrogin-1), and Caspase 3, all upregulated in numerous rodent models of muscular atrophy including disease, immobilization, hind limb unloading, and spaceflight [9–22].