Since MG132 was able to down-regulate the expression of MuRF-1 and atrogin-1/MAFbx-1 in terminally differentiated C2C12 cells, we next evaluated the in vivo effect of MG132 on the expression of these ligases in our immobilization-induced skeletal muscle atrophy model. The gene discussed is TRIM63; the disease is muscular atrophy.