TRIM54 and cancer: In mammals, several E3 ligases, such as the F-box proteins Atrogin-1/MAFbx, MUSA1/Fbxo30, and Fbxo21, and the TRIM proteins TRIM63/MuRF1, TRIM54/MuRF3, and TRIM32, are involved in quality control and degradation of myosin and other sarcomeric proteins in various catabolic conditions, such as disuse atrophy and recovery, cancer cachexia, and muscular dystrophy27–30.