Julienne and col. in 2012 studied the mitochondrial activity of skeletal muscles in murine models of cancer cachexia based on the ATP / Oxygen ratio and concluded that muscular mitochondrial oxidative capacities were reduced by decreasing the activity of complex IV, responsible for muscle loss and accumulation of free fatty acids in muscle (myosteatosis) since less oxidized by mitochondria. They also observed that the expression of MURF1 and MAF-Box (proteolytically active ligases) was increased in the muscle of rats with cancers .