liver

The liver is the largest organ in the body. It has a number of functions:

It is a metabolic mill and storage facility. It processes and stores nutrients absorbed out of the bloodstream as it flows back to the heart from the gut. These are released as needed back into the bloodstream.
It is a detoxifier. It breaks down and excretes various drugs, toxins, and poisons. It also removes, processes, and excretes various waste products of normal body metabolism from the bloodstream.
It is a blood filter. It is an important part of the system of lymph nodes, spleen and liver that filter out germs, both viruses and bacteria, out of the bloodstream and the body fluids.

Infection or inflammation of the liver is called hepatitis.