MUL1 and rhabdomyosarcoma: In parallel, we found that the down-regulated Forkhead box O1A (rhabdomyosarcoma) (FOXO1A) gene was involved in the catabolic pathway together with Myostatin (MSTN), Tripartite motif containing 63 (TRIM63 or MURF1), Proteasome 26S subunit, ATPase 6 (PSMC6), Ubiquitin like modifier activating enzyme 1 (UBA1), Ubiquitin conjugating enzyme E2 A (UBE2A) and Mitochondrial E3 ubiquitin protein ligase 1 (MUL1) genes, involved in the ubiquitin-proteasome degradation system FOXO1A-dependent.