When cancer cells develop in blood-forming tissues, such as bone marrow, it is called leukemia. There are different types, characterized by the kind of blood cells affected and how severely the disease progresses. The exact cause of leukemia is unknown, and symptoms can include fever, night sweats, and frequent infections. Treatment is individualized, but can include chemotherapy, biological therapy, and radiation.
(Click Leukemia for more information on this topic, such as how a diagnosis is made, the different stages, risk factors, and more.)