The lymph node is a small, bean-shaped gland that raises our immune response when exposed to pathogens that can sicken us. We have hundreds of them, located at different sites around the body – under the chin, in the neck, in the armpits and groin. They filter out inflammatory substances and release white blood cells, helping us fight infections and also cancers.However, as important as the lymph node is to our good health, it is little-studied compared to the large organs.