CELL DIFFERENTIATION, or cellular differentiation, is the process by which the cells of a multicellular organism develop the specialized abilities required by each of the organism's several structures. In the context of stem cell biology, it should be noted that the two defining characteristics of stem cells are the ability to pass through several mitotic cycles without differentiating—a property known as self—renewal—and the ability to differentiate into any mature cell type. This property is known as totipotency. There are some cells that can differentiate into many, but not all, mature cell types. Although these cells are not totipotent, they are occasionally considered to be stem cells and are called multipotent.

Cell differentiation occurs via the differential expression of cellular genes, so that the cellular proteins formed ...