Hematopoietic Stem Cells

Abstract

(First of Three Parts)IN man, most tissues consist primarily of differentiated cells that normally show little evidence of proliferation and self-renewal. However, the gastrointestinal mucosal cells, the skin and the hematopoietic-lymphoid tissues continually renew themselves and thus proliferate and differentiate extensively. In each system, a small number of stem cells have the capacity for self-renewal and differentiation, and the more mature cells are derived from these stem cells. Derangements of stem cells or their regulators could result in serious illnesses, and many diseases of the hematopoietic system appear to be stem-cell disorders. These diseases include aplastic anemia, chronic myelocytic . . .