A consistent finding in the literature is the decline in muscle PDC activity in tandem with the increase in muscle PDK4 protein expression when muscle is exposed to changes in FFA and insulin concentrations, such as during fasting, pathophysiological conditions (e.g., type 2 diabetes), or during pharmacological intervention with, for example, peroxisome proliferator-activated receptor (PPAR) agonists or statins [10,23,24,32,33,34,35]. Here, INS is linked to type 2 diabetes mellitus.