Can Human Hematopoietic Stem Cells Become Skin, Gut, or Liver Cells?

Hematopoietic stem cells maintain hematopoiesis and reestablish blood-cell production after bone marrow transplantation. Abnormal clonal expansion of these stem cells may result in chronic myelogenous leukemia, polycythemia vera, and the myelodysplastic syndromes. Stem cells also exist in other regenerating tissues and are considered tissue-specific: neural stem cells give rise to neurons, astrocytes, and oligodendrocytes; gastrointestinal stem cells give rise to absorptive, secretory, and endocrine cells within the gut.In contrast, embryonic stem cells, derived from the inner layer of the blastocyst (the stage of development that occurs seven to eight cell divisions after the egg is fertilized), are totipotent and . . .