NR3C1 and myopathy: The role of glucocorticoids in myopathy for these systems is driven by transactivation properties of the GR (where the GR functions as a transcription factor), which upregulates muscle atrophy and protein catabolism pathways such as the E3 ubiquitin ligases muscle atrophy F-box (MAFbx, encoded by Fbxo32) and muscle RING finger 1 (MuRF1, encoded by Trim63) (Bodine et al., 2001).