An example pathway of compartmentalized human metabolic network: Valine, leucine and isoleucine degradation pathway. The reactions in black and not highlighted are in mitochondria. Those highlighted in light blue are in both cytosol and mitochondria. The reactions with uncertain location (existing exclusively in "uncertain" or in "uncertain" besides mitochondria or cytosol) are highlighted in grey boxes. The reactions revised in the steps of revision of type c reaction, gap filling, IRLR revision and literature-based revision are in purple, dark blue, green and red, respectively.