Interestingly, an increase in skeletal muscle AMPK activity can also activate the expression of atrogin-1 and MuRF1, and induce muscle fiber atrophy [for review see [44]], while nNOS has been implicated in the induction of atrogin-1 and MuRF1 gene in various muscle atrophy models [45,46]. The gene discussed is FBXO32; the disease is muscle atrophy.