Chronic granulomatous disease results from one of at least 410 identified mutations in the genes that code for an enzyme called phagocyte NADPH oxidase. In normal individuals, this enzyme allows a certain type of white blood cell, the phagocyte, to produce toxic free radicals for use in killing bacteria, fungi, and other infectious organisms. Phagocytes normally work by engulfing or "eating" these organisms ("phagocyte" literally means "eating cell"), then killing the organism with free radicals. Without the free radicals produced by the enzyme, phagocytes tend to surround invading organisms, forming little clumps or nodules called granulomas (or granulomata). The presence of numerous granulomas gives CGD its name.