The lymphatic system is part of the body’s immune system, which is responsible for keeping the body free of disease. The lymph nodes throughout the body are connected by a network of lymph vessels. Lymph is a fluid found within the lymphatic system that contains lymphocytes, infection-fighting white blood cells. In the nodes, bacteria and other dangerous substances are filtered from lymph before fluids are returned to the bloodstream. Two types of lymphocytes are B-cells and T-cells. B-cells help the immune system by producing antibodies to eliminate infection. T-cells are important in regulating the immune system and in fighting infections. Non-Hodgkin’s lymphoma is a cancer that develops in the lymphocytes. The primary types of non-Hodgkin’s lymphoma are classified according to the lymphocyte that is affected: B-cell lymphoma, which is most common, and T-cell lymphoma. Cancer of the lymphocytes interferes with the normal immune process, leaving the body unable to fight infections, and allowing bacteria, viruses, and other disease causing agents to overwhelm the body. Simple infectious agents encountered on an everyday basis that normally would not even be noticed, are now debilitating and in some cases, life-threatening. Because the lymphocytes circulate throughout the lymph system, the cancer can spread to other parts of the body, resulting in other organ function failure. Symptoms of Non-Hodgkin’s lymphoma include swollen lymph nodes, fever, night sweats, chills, fatigue, unexplained weight loss, and facial swelling. Non-Hodgkin’s lymphomas are described as either being aggressive, growing and spreading quickly with severe symptoms, or as indolent, slow growing with few symptoms. Treatment depends on the stage and type of lymphoma. Standard therapy includes radiation and chemotherapy. Experimental therapies include hormonal therapy and high-dose chemotherapy with stem-cell transplant. Most patients with Non-Hodgkin’s lymphoma can benefit from some type of treatment. Complete cure is possible for many patients; for others, treatment can provide relief of symptoms and extend life expectancy.