False-color scanning electron microgra...

False-color scanning electron micrograph (SEM) of white blood cells from a patient with acute lymphocytic leukemia. In this disease, certain types of white blood cells are overproduced, and these abnormal cells suppress the normal function of white and red cells, increasing the susceptibility to infections. (© Professor Aaron Polliack, Science Source/Photo Researchers, Inc. Reproduced by permission.)