The liver is not useless. It is one of the most vital organs. Nobody can survive without one.
They :
process digested food
Regulate fat, amino acids and glucose levels in the blood
Fight infections
Clear the blood of particles and infections
Neutralise and distroy drugs and toxins
Produce bile
Store iron, vitamins and other chemicals
Breaks down food and turns it into energy
Makes enzymes and protiens which are responsible for all the body's reactions