This is the first book on a very hot topic: the phenomenon of asymmetry in cell division in plants and animals. Cell biologists have recently become aware that the asymmetry of cell division is an important regulatory phenomenon in the fate of a cell. During development, cell diversity originates through asymmetry; in the adult organism asymmetric divisions regulate the stem cell reservoir and are a source of the drift that contributes to the aging of organisms with renewable cell compartments. The book describes the phenomenon in different organisms from plants to animals and addresses its implications for the development of the organism, cell differentiation, human aging and the biology of cancers.