Non-Hodgkin's Lymphoma is a type of cancer of the white blood cells where either B-cells or T-Cells grow uncontrollably, clogging the lymph nodes and causing them to swell. If left untreated, the abnormal white blood cells will eventually overwhelm the immune system, leading to death. Like most cancers, Non-Hodgkin's has no clear cause, but often runs in families. It is also common among those who are Immunosuppressed or those who suffer from a large number of infections and have a weakened immune system, particularly patients with AIDS.