And there's no avoiding increased risks of cancer - to liver, gall bladder and the lymph system.

CNN: THE GREAT DIOXIN SCARE

Arlen Specter (R-PA), who is fighting a recurrence of Hodgkin's Disease, a cancer of the lymph system, also commented on the diagnosis.

NPR: Doctors Say Ted Kennedy Has Brain Tumor

There are filters at certain points throughout the lymphatic system called lymph nodes, which usually exist in grape-like clusters.

CNN: What is Hodgkin lymphoma's effect on the lymphatic system?

To find the body's secret weapon, scientists remove cells from a lymph node - a part of the circulation system used by immune cells, but which also often forms a "staging post" for cancer as it spreads around the body.

BBC: Supercharged cells fired at skin cancer

Gilenya works by a totally new mechanism to block some immune system t-cells from escaping from the lymph nodes.

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