Light micrograph of hairy cell leukemia. The cancerous white blood cell at center has a large nucleus (purple), pale cytoplasm and rough "hairy" edges. To its left is a normal white blood cell with a bilobed nucleus (purple). Red blood cells (pink) are also visible. In leukemia bone marrow and other blood-forming organs overproduce certain types of white blood cells. Whereas normal white blood cells play a protective immune-response role, leukemic white blood cells are immature and abnormal. they suppress normal white blood cell production and lower the body's resistance to other infections. LM 500x at 35mm.